Man prefers masturbation to sex with GF

I have a very embarassing issue. My BF of a yr. will avoid having sex with me but I will find him daily masturbating. When we do have intercourse he rarely is able to orgasm. Short version of long story. 2 years ago he got out of prison (10 yrs) (I was not aware of this until few months into affair and I have never had any experience with anything like this so all new to me) Now, from what I gather (refuses to talk about the issue) He only masturbated (dry) for 10 years. He says it is not me but he also says that he can't orgasm because I am too wet. (I am extremely wet) At this point, my confidence is shot, and I am so deeply hurt that everything is all messed up. I try to tell him how I feel but it doesn't do any good. He wants to avoid the issue. Why does this man want to stay with me if he doesn't desire me? Am I the problem? I have a very healthy (or maybe too healthy) a sex drive. It is so very hurtful to feel this way. This issue as well as many others from living with someone that is an ex con has just crushed me and thrown me into depression and I am desperately searching for information. Please help.