Guys I need some help. I am not as horny as I use to be and it is really effecting my relationship First some info. I am 19 165lbs and 5"11 and lately I just have not been horny as I use to be. I have not been  masturbating nor have I been having sex. My girlfriend feels like I don't want anything to do with her. I love her with all my heart. (we have been dating for almost a year and a half) but she is totally done with me. She thinks she is inadequate. How can I reverse this problem? 

Sorry for the wall of text I am quiet desperate here. 