Hey! It's great you get to see a psychiatrist/therapist!
Yeah, nervous is quite usual in a situation like this, maybe you can write down some things on a piece of paper and bring with, or even print this out (like what you wrote here, or a bit more), to know what to mention? You could also give him/her the note/essay if you'd 'freeze up'?
You could also ask if there is CBT (=cognitive behavioural therapy) or such available, it's way better to get therapy, not just meds...
Please stay away from weed, it can make things worse...
This doctor seems concerned and caring, even if it may seem like a bad thing it's probably a good thing if you'd be able to get some good support/therapy... Take care and let us know how it goes!!