How do I stop having panic attacks when I see my crush?

You need professional care. As you know you have ADHD and what Asperger's, you've apparently been diagnosed by competent MDs. So now you need proper therapy. [Have a grandson with Asperger's and a wife with ADHD.]

What you have will not just go away and typically cannot be resolved through self-treatment.

Pretend you two already know each other and your friends. This mental detachment is a way you tell yourself you've been there done that and it becomes familar/second nature to you. Treat her like an old friend.

young girls like older guys it's a fact, you're the one in control here you shouldn't be nervous just take your meds and you'll be a ok

Though it's only a 4 year difference, stay away from this relationship for at least another 3 years or you'll find yourself making love to a man in an orange jumpsuit.