KP issues... Socially and mentally.?

I have had KP since I was born and everybody made fun of me at school and it really lowered my self esteem, and I don't have any. I constantly agree with all the bad things people say about me and it helps me, in a way, feel safer. I haven't felt good about myself in a positive manner since before I entered school. I've been constantly picked on and put down and felt like **** because of my skin disorder and it really has taken a toll on me. I began experimenting in drugs and alcohol; I fear it'll only get worse. I don't see myself living because it is of course a very shallow world, and if you don't look good, you're not... Liked. And all my life, that's all I wanted. Now, I met a guy outside of school and I really, really like him. He's the first person I've ever really liked and he likes me too, but I hide my skin, so if he sees it, it might scare him away. And I know no one will ever want me because of my skin, but I really like him, like I said. He really makes me happier and optimistic and without him, I'd be a pessimistic ******, to be honest. He invited me to a party and it's a swimming pool one. I feel so bad about it. I don't know how to hide my skin and I don't want to feel ugly like I usually do. I really want to have clear skin. How do I make it go away so that it isn't noticeable?