*I disagree with carpe diem and agrophobia completly, people who this happens to usually believe its their fault, but it isnt, not pushing him away and being his gf at the time definately does not make it your fault.
For example, if someone came up to me with a knife and tried to mug me, i would probably do what they ask, that doesnt make it my fault i was mugged, even if they asked me how i would react, and itold them i would do what they asked, and THEN they mugged me, it still wouldnt be my fault, the same applies for you,
fear makes us react in very different ways than how people would expect, and you can ask anyone else this has happened to, theyll tell you they reacted in the same way.
please dont believe this is your fault, and dont believe you need to feel disgusting about yourself or that it makes you a dirty person, or anything less as a human than you were before.
it sounds like you really need to talk to someone about this, try a teacher, counsellor, parent etc,
your friends wont be experts on this subject, so if you talk to them, only go for support, not advice, its best to talk to a teacher or counsellor, as theyll know how to best handle the situation ,
good luck with everything
PM if you need to
P.S it doesnt matter who considers it as rape or not, if its happening and making you feel horrible, then it shouldnt be happening, although, this clearly is rape, nt just in my opinion, but also through the eyes of law