So I’m looking for a movie that i have watched on HBO some 10 years ago.

The plot is that there is a guy, who looks like normal human. He’s part of some different species that I think feeds on humans. But somehow, he has found out a different way to live. I think it’s because he had fallen in love. Also, i should mention he visits an old dying guy, from the same species that has also managed to live without harming humans. I believe that they can also shapeshift (sort of like in the game Prototype). What I also remember is that others are trying to find out the protagonist’s secret and he’s being killed again and again ( I think it’s something like that) but the day only resets for him.

The movie is in colour. And I think that’s all i remember. Hope you can help me. Thanks in advance!