It's a movie about a guy who has hemophilia, well I think he has hemophilia because if he gets a little wound he can die because he won't stop bleeding. To cope with his condition he kills his girlfriends and takes their blood, he feels better for a little while after drinking their blood. In the end he falls in love with a girl, and she loves him too, but at some point he tries to bite her neck, she gets scared and tries to get away. But the man closes the door before she gets out and says something like "please don't, i'm sorry, i love you". The movie ends with the girl stabbing the man in the hand with a knife or a pen and kills him.

I really really need your help! I think I saw the movie like 6 years ago, so the beginning of the millennium:)

I also seem to recall that the man used to wear a lot of turtle necks.

Hope you can help me with this mystery!

2000s:
Vampire Films

http://en.wikipedia.org/wiki/Vampire_films

Thanks but it's not a vampire movie, but the guy still sucks blood, he needs to because his own won't coagualate. Any other suggestions?

Bit of a long shot... might be The Wisdom of Crocodiles from 1998, a vampire flick with Jude Law and Elina Lowensohn (herself no stranger to the vampire genre).

Oh my god! You found it! I've been looking for this movie forever! Thank you! THANK YOU!

Well, I hope it really is the right answer. If so, I got lucky because I just read about it two days ago in one of my reference guides.

It's the right movie for sure:) seriously thank you sooo much! It was so annoying not knowing what movie it was.