I have never talked abt this b4..pls help?

Hello people..My name is Prity..and I am in such a soup..don't know wat to do..I am 16 and my cousin is 12..Once we went to see a movie..During the movie..my cousin felt sleepy and so he kept his head on my lap. But suddenly his hand started crawling in my t-shirt.and the next moment I knew..he was sucking and munchin my boobs..I wouldnt deny..i liked it too..So we continued..Now once wen we were playing on the terrace..even his freind started doing the same thing to me..and suddenly all his freinds jumped over me and started sucking my boobs.I felt good at that time but now I feel horrible abt the whole thing..And the main thing is all dis kids arent sexual at all. They see it as a maternal thing than a sexual thing..And they want me to continue with the Act..pls help me..i didnt knew things would go out of hands so fast.