First off I am so sorry you have had to go through that experience.
Are your parents aware of what has happened to you - they should be let know hun.
This becomes one of those technical questions.
Technically no matter how shallow you were penetrated, which you say that you aren't a virgin.
However, from your description it sounds like he wasn't able to penetrate you and the head of his penis was just in the entrance of your vagina - in which case you are still a virgin.
Now, technical aside, my opinion on this...
I say, yes, you are a virgin because you were unwilling and so young and full penile penetration did not take place.
Virginity is physical only on a technical level, so while for some women their physical virginity may have been taken from them, they still haven't given their emotional virginity (ie first "normal" sexual encounter) - and that's what counts.