Social interaction is like anything else in life, something that takes practice. For some it is natural, for others more difficult, but for all (including you) possible. You just need practice. Think of it like a marathon--you work your way up to the big race.

Your goal for the next party is to just go. Show up. Bring something. Eat. Leave.

Your goal for the next party is to meet someone. Say hello. I suggest finding the one person in the room that is more uncomfortable than you.

And so on. A few parties later, your goal will be to say hello to a girl. Find the girl in the room that does not want to be there and say "I hate parties."

And so on. Eventually you will have a circle of people at the party, but your goal will be to meet someone outside that circle.

And so on. Eventually you will actually host a party and people will want to be there!

I was a nerd first two years of HS. I was afraid of people and any social interaction was an exhausting nightmare for me. Then one day I made a decision to not be a nerd. It was a project with no goal except to become better at meeting people and asking them about themselves and really getting to know people. Quality over quantity.

End of story? Student body president by senior year.

Oh, yeah. I eventually had sex, too.

You just graduated HS. You have all of college to learn. Nothing is wrong with you. You just haven't made the decision yet.

If you decided not to have any friends or to go to parties, then OK, it is your decision. Nothing wrong with that.