I was diagnosed with ADHD and started on medication at 12, but not really told anything about what it meant for me or how to deal with it, and when I was 18 -literally when my parents dropped me off at college- was told I was autistic
Edit: don't forget to upvote posts here so they're more visible and people can find the community!
You should make a post asking about that if you're comfortable doing so! :D
I'm sure you're not alone in your shoes here