In terms of tweaks to advice and guidance from professionals - I think really it's more of a rewrite. It is hard having the self awareness to see what is and isn't helping. It can take time, but the harder process for me has been getting other people to respect that. Mostly for me this was prediagnosis. One Psychiatrist gave me the freedom a d the space to focus on the important things. Everything that was irrelevant he accepted in whatever way I was comfortable. I sat on the floor, I brought things to fidget with, I didn't make eye contact, I wrote 80% of what I wanted to say...and all of that was perfectly fine by him. He saw me once a month and spoke on the phone etc in between if needed. If I said something wasn't working for me he accepted that and explored another plan. This gave me a really good grounding in working out what is helpful to me, how I can tell and what it feels like to have someone respect your judgements and work with you. During that time I had some CBT. As far as I know CBT is rooted in theories that don't hold for the autistic brain. I was given homework to stand in a supermarket to prove to myself it was t so scary. But all it did was reinforce I couldn't cope with the sensory overload. I was consistently asked - if I asked 100 people x question, what would they say? I suppose a tweak here would be to consider - if you asked 100 autistic people, but I still think you might have had to actually ask them for me, because I wouldn't do well at guessing if they agreed or not. I now go against all of there advice completely and use every strategy and "crutch" I can to get through situations that are difficult.
Later I saw a different Psychiatrist after them and he wasn't able to allow any of the things I had been used to, written communication was annoying so no longer valid, the only place it was OK to sit was the specific chair he said and he wouldn't even write down the gap to the next appointment so I could show it to the secretary to make the appointment. He pretty soon decided I was too 'difficult' and asked someone else to see me instead. When they messed me about I walked away. I decided now with a diagnosis, I needed to work out what I could do on my own and accept that apart from that one person - they were making things worse not better.
I didn't get any post diagnosis support because there isn't a y here and I had discharged myself from Psychiatry by then. It did help that I felt I had to make it work, because no one would accept the level of s/h I had been doing with no Psychiatrist involvement. But for a while before I'd been experimenting with what works for me before it was official while I still had a Therapist.
The first major revelation for me was allowing myself to do whatever I would do post s/h first. I used to reason that there was no time, it was stupid, I had to be up in the morning etc etc etc. But most times I'd get back from the hospital, have a takeaway because I couldn't bring myself to cook and curl up under blankets, sometimes loaded with books and watch Disney or how its made videos. Even though it was hard I decided that I had to have seen that through first. Then I found I didn't get there. I made a weighted blanket and used that, I started to want to s/h less. Then I stopped surpressing stims at home. Shouting a made up word - fine, jumping - fine, spinning, flapping, rocking, anything fine - because it doesn't hurt anyone. I also investigated pretty much every stim toy and sensory aid I could find. That reduced the times I consider s/h to about 4times a year which so far I have managed and when I have been significantly low and that is definitely on the horizon - I take temazepam and go to sleep. Usually it's better in the morning. To be honest it's a slow process, but it is one that is worth finding space for. I was convinced I'd never make 30, I was sure I'd spend my life screwing up until I died. But now, I'm engaged, I have a full time job I love, my employer is funding my degree, I have friends and on average one bipolar related high and low a year. I can work with a different Psychiatrist just to get the bipolar stuff right, knowing I can walk away if I want to.