I totally get it. I used to feel so freaked out by girls I would become froze up and couldnt think and Id have an anxiety attack and my thoughts would be jumping and it was really wonderful
I think the right girl for you helps you feel comfortable with yourself but we dont want them to fix us, just understand and be caring. You'll get a vibe from her and she'll relax you somehow.
Dont worry about your looks. That wont matter to her. I live in my head a lot too lol.