Looking for Advice

Hey everyone I know there are probably 500000 posts a day like this one but ill annoy you all with 1 more anyway :) 

I am 23 and all my life I have been different, a social outcast of sorts in primary school and then into secondary school. I learnt that if I acted a fool I "impressed" my peers and made friends through being the class clown. Although outwardly I seemed eccentric on the inside I was always a very anxious person. Struggled to fit in, couldn't make conversation and my only hobby was playing xbox 12 hours a day.  This ended with me being kicked out of school permanently.

Fast forward to 16 I joined the Army, I was physically fit enough but once again felt outcasted from the other lads. I just didn't fit in and quit within 2 weeks due to not emotionally coping with this new life. I then became pretty depressed and even more socially anxious. All through my life even now I have this overwhelming feeling I am different, I don't fit in. I only enjoy very few things right now that is PC gaming and motorbiking. I am on benefits but cower at the prospect of being removed from them and having to go back out to get a job. It's not that I don't like working or am lazy I just never fit in with anyone. I have never made a friend I have been able to keep for long. I can't make eye contact with anyone my body rejects it and makes me look away. I have always complained of memory issues and struggle to learn new information but can somehow remember numbers amazingly. I know atleast 15 phone numbers off by heart, I can remember my NI number, all my debit card details etc etc. 

The main overwhelming thing for me though is the complete lack of social skills. I only realised when working at mcdonalds how bad I was at it. I realised that when trying to make conversation with people I always talked about my life experiences like joining the army. Never once did it click that I probably seemed self absorbed but in reality it was because I didn't know what else to talk about. To this day I still have no idea how to make normal conversation with people. I always end up talking about something happening in my life, or my motorbike. When I feel anxious which is a lot I twiddle my thumbs and look at the floor without realising it. I did an autism test and scored 47 / 50 and I answered it as truthfully as possible. When I made some online "Friends" do the same test they all scored less than 10. I am under a mental health team with a diagnosis of antisocial and borderline personality disorder which never seemed to fit me nor does it help me. But when I read autism symptoms in adults it just clicks. On some of the tests some of the questions are weird ones but I think wow yeah I do that. For example textures feeling offensive of my skin. I have always cringed when touching many things like anything made of wood or polystyrene.

I brought this up with my mental health worker but they seem to shrug it off, but I can't shake it off and no offence to anyone here but of course I don't want to be autistic but if that is the case then I would at least like to know why I am different and know there is a reason for it. 

Sorry for the wall of text and I probably missed out a lot of information but I just want to know from actual autistic people if you relate to anything I have said? Many thanks Danny