Feeling like I am on the spectrum

How can I get checked ? Or what kind of doctor do I see I have to send the paper of the disability I have to the ssi correct or how does it work ?? There’s something wrong with my head and I’ve been feeling migraines for a year and I feel weird like I get out my brain 🧠 for a couple mins and return but that feeling I’ve been feeling since I was a kid but was shy to tell anyone