Boyfriend not interested in sex. Very long :(

Me and my boyfriend have been together about 4 and a half years. We are long distance only get to see eachother about twice a year. So our main way to be sexually intimate with each other is phone sex, touching ourselves on video chat, stuff like that.

Well about two years ago he basically just stopped all of the things we do sexually with each other. He would strike things up occasionally but it would be like every two months. Anytime I tried to start anything up I get turned down. Back then he'd watch porn (I don't have a problem with it) but refuse to be sexually intimate with me. He told me he didn't want to have Skype sex or phone sex because his roommate could possibly hear him through the walls (which is a BS excuse). He could've turned on the tv he had in his room to drown out the noise.

When me and him meet up during our twice a year visits we do have sex and it's good. But this last time something seemed off. Like he could've gone without doing it. Like he wasn't interested at all in it. After not seeing each other for about 6 months he wasn't all over me like he usually is. It took him five days to initiate anything. I didn't want to initiate anything because he seems to turn me down whenever I initiate it. And the sex wasn't the best. He seemed to be not fully into it perhaps like he was only doing so because I'd be disappointed if it didn't happen?

I have tried to talk to him about this. He just tells me he isn't in the mood. So for the past 2 years he hasn't been in the mood for me? He claims he doesn't even watch porn anymore that he isn't interested in anything sexual. He is stressed about work but he used to be just as stressed back when he was all over me. He says he is going to try some lifestyle changes but he never commits to them.

I'm honestly so sexually frustrated. I'm also starting to resent him a bit. It doesn't feel like he's putting in the effort like it doesn't matter at all to him. He knows how frustrated I am because I bring it up and he panics and says he loves me and doesn't want to lose me and then says things along the lines of that he is trash and I deserve so much better which doesn't help the situation.

Being wanted sexually is very important to me in a relationship. So this is impacting me very negatively. And it's been going on for 2 years. Maybe even longer than that. If anyone has gone through something like this and has some helpful words I would greatly appreciate them.

Sorry for the long post just at my whits end.