Seeking assessment at 25, GP denies adult autism assessments exist?

Hellooo I'm sorry if this is the wrong way to post here, like if I'm meant to do an introductory post first before coming here but as I was typing it out all the things I wanted to speak about and ask in here were all pouring out so I figured I may as well just post here if that's okay!

Edit; so sorry that this is so long! I get carried away wanting to get enough detail in for it to all make sense

So, for a number of years I've been pondering why I was becoming a lot more drawn to and felt able to be a lot more open with my friends with autism and ADD/ADHD, and why a few of these friends outright ask if I was autistic or had been diagnosed with ADD, the friends who asked don't even know each other, so I thought it could be a big coincidence or maybe something I should look into, it's been a few years since the last person asked so I brought it up in a GP appointment, and asked how one would be assessed for ADD. Her response was just that she had "seen plenty of children with ADHD and they don't settle like you are settled so you don't need to worry about that"... Right, thanks, I'm an adult not a child for starters and I asked about ADD not ADHD, but okay. Life went on.

Fast forward to last year to now, I've been struggling more than every with what I've always assumed and been told were anxiety related issues, but it didn't make sense, how could anxiety make me want to rip all my hair out because it feels greasy and touched my face? How could anxiety make me break down and cry because my clothes all feel coarse and horrible and make touching velvet make me want to puke? How could anxiety give me such restricting food aversions my entire childhood and teen years, based on textures making me feel incredibly uncomfortable and, again, sick? It could certainly explain some of my social issues, sure, but it never did explain why I still had trouble with people that I don't even feel anxious around. So I looked into ADD again, and came across some youtube channels that spoke about autism in women and the similarities and differences in autism in men and women, and spoke about their own experiences and how they came to realise they could be autistic (so far I have only seen women speaking about this who were diagnosed in adulthood) and I have been bawling my eyes out at every tiny revelation. It was like they described my whole life struggle, everything I've ever had no explanation for suddenly had a possible one, so I'm fairly sure that I'm autistic, I told my counsellor and she agreed to be an advocate for me during a GP appointment to ask about getting assessed and helped me to get some things written down ready to present as "evidence" all seemed well and hopeful and I feel like if anyone here is still reading at this point you might guess what's coming next

Covid means my GP isn't currently doing in-person appointments so my counsellor got in touch with the surgery to ask about setting up a 3 way call or zoom conference (her own GP does zoom conferences with people who need someone else in their appointments) and it was all just a bit confusing from there, she calls them for me because I just cannot do phone calls a lot of the time if its me calling them, but they need permission from me which is fine, the receptionist calls and says I'll need to wait for a doctor to call and I have to ask them (alone) for what I want to do in this appointment because they're confused for some reason about what my counsellor was asking. Issue here is my whole need for her to be there is because there's only one doctor at this place who doesn't try and talk me down and tell me there's nothing wrong unless it's a physical issue I'm in for, and I stammer really really badly trying to explain things so she was going to be there to help me keep on track and give prompts if I got overwhelmed, and politely ask doctors not to interrupt me (they always do). So I waited for this call hoping it would just be a case of "Hello yes I'd like _____ to be in my appointment with me, when is a suitable time for this", confirming details for security etc but nope

Gp calls and is really pressing me for what the appointment is for and I keep telling him I'd like to wait til my counsellor is present to discuss details but he's just repeating that if it's mental health suppoort I want, there's no need for an appointment and he would forward me onto the MH team, but I keep telling him no, that's not what I need but I need her there before I explain in detail. Not budging, fine I guess from his perspective it's an odd situation and if normal appointments were allowed it would be a lot more straightforward she would just come in with me and that would be that, so I tell him I'm seeking assessment for ASD. What a big mistake on my part thinking he would let it go and just book the appointment with us, he tells me that an adult assessment doesn't exist, I tell him my counsellor found somewhere who does it right here in our county, "hmmmm, no, I think probably not". He insists that I cannot possibly be autistic, he or one of the other GPs at the practice would have picked up on it in childhood, "it's a developmental disorder not a mental health problem so I'm not sure why your counsellor has this idea in her head" (I know it's developmental, I just think everyone has overlooked it in me and possibly I've masked my way to this point in my life). He also insists that "autism is only really an issue in education and since you're an adult out of education now, you won't be struggling with it even if you were autistic"...

A quick side note, this particular doctor is the one doctor I've refused to see since I was 12 after he berated me for not maintaining eye contact with him during the appointment... I can't believe the irony of him insisting he knows for certain it's not a possibility after that being the last contact I ever had with him til this phone call

So I guess I'm quite stuck. This GP is the only one I'm in the catchment area of as far as I can see, I can always complain but I'm not sure what good it would do in terms of me being able to get an assessment. My counsellor says that he isn't allowed to refuse, and that it's likely he will make getting an appointment with an advocate difficult because he couldn't possibly be this unprofessional in front of another professional. Other doctors aren't great there for anything that isn't a physical ailment and even then they're questionable (my gallbladder became dangerously infected and had to be removed due to them ignoring the pains I went in for multiple times saying it's just indigestion) his wife at the practice is the doctor I mentioned earlier who dismissed my question about ADD, it's generally just really old fashioned and the doctors don't ever seem to want to deal with anything that can't be solved with a prescription. 

I was really hopeful to potentially have an answer to all these things I've had such huge struggles with in my life and I'm not sure how to pursue it now, I currently have no job partly due to these issues, I left college twice because of them before eventually completing a course, then the same thing happened with uni because I just am so easily overwhelmed I can't seem to cope with anything, I left my job this year because of it all, and obviously am having the worst time trying to find another, knowing full-well that when I get one I won't cope well with that either because it'll involve either people or telephones. Animal related jobs want quals I don't have and can no longer get, I haven't got the skills for much work that can be done at home so I'm just desperate to at least have an answer to why I struggle so much so that I can work toward fixing it or at the very least know what I need to ask of employers to help me feel comfortable enough in a job to do it well. All this has made me beyond depressed this year and of course covid restrictions won't be helping that but it's largely down to the fact that I feel completely useless and my life reflects it, at least when I was younger I could still live with these issues but now I can't pay the bills because of them, I am just so desperate for an answer, or in this case just where to get answer