Cancelling plans last minute due to fear of social aspect

Full disclosure, I gave up on having friends  a long time ago, so maybe I am not qualified to comment. I went to 'leaving drinks' a few weeks back for someone at work, stayed for a little over an hour and had a good meltdown when I got home.
I am not successful when it comes to socialising.  I think I understand the theory, I just can't manage it in practise.

Are you able to organise smaller meetings, one or two fiends somewhere quiet?  I suggest telling them that the noise and complexity of trying to manage interacting with more than a couple of people at a time is really hard, even though you wold really like to see them.

This is like me. I’m going to stop saying I’ll go to things as I know I’d rather stay at home and I’m happy doing that. Peace.,

I do this on a regular basis and have done it today. I always end up overthinking about it asking myself "am I really that bad a person?" and "why can't I just be understood?".

Why I don't have many friends because I make plans but then when it comes round, I get really anxious and fatigued. I suffer from Anxiety and Depression anyway, and it just gets heightened. 

There is one friend who understands my Autism, but after today I'm asking myself, does she really? 

I’ve tried to adopt a ‘no dread’ calendar. Basically, if the social appointment is something that I will dread or find too taxing, then I don’t agree to it. Lately, I try not to confirm attendance to anything until the day before, so I can see how I feel and make a decision accordingly. If the others are accepting of your autism, this should be tolerated, without anyone taking it personally. No one with your best interests at heart will want social arrangements to tire you out or cause you to burn out. 
Regarding masking less, gosh it is hard. I’m so used to putting on a performance whenever I’m around literally anyone that it is hard to even know what my non-masking self is actually like. What I do know is that I allow myself to make less eye contact now, and try to be more accepting of my stumbling over my speech and such like. Slow steps, but I feel more comfortable with it, so I guess it is less masking behaviour, 

In short, masking is pretending to be normal, appearing neurotypical, and hiding any aspects of your autistic behaviour to try and fit in with others. 

What's masking?

I've found through experimentation that there's a maximum number of social hours per week I can sustainably manage. That includes any situation in which I have to speak to someone, so if I had to go to an appointment during the week, it eats into the budget. I count video calls as social time, but not texting.

Going over budget is a terrible idea that leaves me feeling burned out for several days afterwards, so I'm trying to stop doing it.

Thinking of it like that helps me to predict what I'll be in the mood for based on how much social time I've had lately. It makes it quantifiable and therefore easier to manage.

My rule of thumb is I need at least 8 hours alone on any given day, and can manage a maximum of about 8 social hours per week. If I break those rules I know there will be trouble. I might also add that 8 days with no social time whatsoever is about the point I start to feel underpeopled, which is less bad than being overpeopled, but can lead to feelings of melancholy and listlessness.

In general I dislike agreeing to attend anything that can't go ahead without me, so I always have the option to drop out without ruining anyone's plans.

I've deliberately been trying to unmask for half a year. First it started without autistim in mind, although I suspected it, but it wasn't in the picture. It started as a healing journey to focus my efforts on figuring out my needs, wishes and preferences over focusing my efforts on figuring out how to be accepted and liked by others. Slowly my autism appeared to the surface. What happens when you unmask is a discovery journey in itself and it depends on so many factors, including how your autism looks like and who are you unmasking with, ext.. but what I think that would probably happen internally in the person is a lot of healing, self-discovery and a feeling that the self is finally united rather than scattered to pieces that have constant fight. It brought me, although it has been very short time in the journey for me, lot of satisfaction with who I am and lots of love to myself. Try to unmask first when you are alone and see what happens, after a while try it with a trusted person/therapist and see what happens..

For social situations, I'm trying to learn how much socialising I need per week, what settings fit me the best and what things in social situations might bother or drain me and how much time do I need to recover from each. It makes it easier to plan them in advance. I also try to look at social situations as "test field" to learn about myself and exactly to answer the question "what happens when I unmask?". I wouldn't recommend to start doing this in places where the consequences might be high like at work for instance. Good luck

I think the better question to ask is what sort of individual or group would give you a sense of being a responsible part of a community? 

We are social beings better in relationship - whether a small select few or a larger tribe. Some of us (myself included) are more extreme introverts who don’t need as much time with others- once a week will do. Though I’ve been known to go much longer.

The art of forming bonds and friendships is often not taught, such as how to invest in another. But I can recall a time in life I just needed to heal. I needed a great deal of time alone and I needed financial help to have this space to learn about myself, learn what I was impacted by, and what I was actually capable of (both good and bad). I needed Time on my terms to grow, essentially. We do not “mature” the same as our NT peers. 

Im not much of a fan of the use of the term “masking” as it’s a Grounded and Recognised term in clinical psychology for what everyone except Autistics do and has been around since Freud. Almost 100 years. Rather, we might camouflage, but poorly. 

I would even go so far as to call it a performance and that IS exhausting. It’s a career choice for some. 

A more important thing to ask is if you see a lifetime of performing around these others. Friends of our partners are often with them for life. It’s OK to start to question if your actions are part of something deeper in yourself that you’re having a difficult time accessing. I have alexithymia and once I recognised this it helped me think about how I was being impacted and what I really wanted rather than “trust” I knew that. It can take a long time to become into ourselves. So it’s OK to let go of everything else for a while and explore this. 

I completely understand where you're coming from and I've done the same myself in the past.

These days I consider if the social event is something that I will enjoy or get something positive from, if the answer is yes then I will go (sometimes have to make myself) because I know I will enjoy it although I will possibly find it challenging and exhausting. I will also make sure I schedule in recovery time afterwards, sometimes that can be several days of really low activity to get back on track. If it is a social event that I know will not enjoy and the only reason I would agree to it is to people please, then the answer is no straight away. My energy is limited and a precious resource and I will only spend it on things that are good for me. That sounds selfish when I write it down but I'm done with draining myself for other people with no reward for myself. I also think it is best to be straight with someone and decline to participate rather than change my mind last minute, it also cuts out the stress of the build up to it. Just my take on it but hope it helps.