Ummmm... Excuse me, but your immaturity is showing. You'll probably want to cover that up dear.
If you don't want your baby give him up for adoption. Trust me, from the sounds of you it seems like the most humane thing to do for the poor little guy. When you decided to be a mother you gave up all the stupid teenage bull and no, if you want to keep your son you can't have it back. Trust me, your friends are not depending on you to be at this party, your friends will have forgotten about you entirely in a few months anyway. The only person who is depending on you is your son. And his needs far transcend your friends, and your own right now.
When you make a commitment to have a child, you make a commitment to care for him properly. Leaving him with someone you don't know so that you can go out, get out of your face intoxicated and then come home and breastfeed? That is so far beyond disgusting it hurts my head.
I sure hope cps finds out about you.