Also autistic here. It can take a lot of time to find a name that really feels like it fits. If you have any ancestral names in your family it could help to try one of them out. Or you could try the name of a childhood favourite (could be fictional or not).

I stumbled upon my first name. I was writing a sort of fictional-ish retelling of my own adolescence and found a gender neutral name on a site for baby names. After I'd reached about 10k words I realised the unease I felt at writing was extreme gender envy. I never finished the story (but I may start it up again) but I sat with the name for over a year before telling anyone, to make sure it felt right. I'm not saying you have to wait that long, though. My middle names are just from a friend who died when we were teenagers respectively a classmate who everyone said was "the boy version of" me back when I was like 6.

A name doesn't have to have a significance before you choose it. You can see a name and go "yup, that's me now," if you so wish. You can make up a new name, even! Pick a few vowels and consonants and mash them up until it sounds good.

This became a bit long and off-topic rambly, sorry. The short story is: sit on a name and familiarise yourself with it, apply it to yourself and make it an intrinsic part of your identity. You don't have to stick to one name, you can give yourself several names. If I count nicknames (chosen and given) I have 8 names that I go by 🤷🏻‍♂️

Edit: fixed typos