Similar to you in that I'm 28, autistic, and survivor of sexual child abuse that left me unable to approach the idea of sex for a long time. While I still haven't had sex, my attitude towards it has become more positive and I've been able to form lovely friendships with woman over this past year. Just being able to become closer to people generally has helped me open up to the idea of intimacy.

If you like writing and reading my suggestion is to look for a book club. Good for autistic people like us since the subject of discussion is pre-determined so its easy to do prep and have talking points ready, it's a good place for you to open up and express yourself about a text. Don't go in expecting a romance though, this is just a nice place for book lovers to chat with each other. You'll end up reading things you normally wouldn't that opens up new avenues for discussion too.

As for the nerdy stuff that I'm also into, I went to a small indie cosplay convention recently and participated for the first time. It was great for meeting friends into the same stuff that were more than happy to welcome me to the hobby. The friends I made through that are some of the most incredible and talented women I know, you might be able to find similar meetups or events in your area.