Ending my marriage

I've been married for over 20 years. I got diagnosed with autism last year (had suspected it for over 10y) and my partner was diagnosed with ADHD around the same time.

I've read somewhere that over 80% of ASD + non-ASD marriages end up in divorce. I don't know how much of it it's true but I'm about to become yet another statistic. 

We tried couple's therapy before my diagnosis and I thought we were on the good path again, but I'm on the brink of a burnout and I don't think I can continue taking the pressure from my partner any more. I'm constantly being asked to perform according to neuro typical standards, to mask my autism, and I've decided to end our marriage as a consequence.

It's really sad because we both love each other and we are still physically attracted to each other but I don't think I can continue. It's destroying my mental and physical health. My partner doesn't understand my limits, doesn't accept my boundaries, I'm constantly being asked to "try harder" (be more social, do more small talk, demonstrate affection e.g. smile, the list goes on and on) when I'm constantly trying beyond my limits already and making myself ill. I've tried to explain that this is ableism, that I can make some small adjustments to a certain extent, but I cannot change who I am. All I can do is mask and push myself to another burnout.

Today I put forward a plan for separation, starting with gradually separating our financial assets while still cohabiting, all the while trying to protect our teenage son who has severe mental health issues and is emotionally unstable.

I did the thing I always do, talked it through with reason, calm in the face of adversity, while my partner was an emotional mess. Then my partner left for a walk and I collapsed into a massive shutdown. 

In the end, I agreed to pause any actions untill we find professional help again. I don't think I will backtrack on my idea to separate - for as much as I hate change and still love my partner. I'm aware that with autism I have a tendency to black and white thinking (this either works or it doesn't), and that might be blindsiding me to the huge benefits of being in a relationship but right now I can't see a way forward. In any case, couple's counselling would help us manage the separation so I'm not opposed to it, even though we tried it before and I feel like I've already said everything I needed to say and listened and understand my partner's side of the story too.

The problem is that I have no idea where to look for a couple's therapist with experience in autism. Any suggestions or referrals would be much appreciated!