My partner and I rarely have sex

And I’ve expressed to him multiple times that it’s frustrating and I want more sex. His response is that it’s about vibe and mood. He says if I smiled more and was happier then he would want to have sex with me more often. I tell him it’s a catch 22 situation that maybe if we had more sex I would be happy and smile more. We have sex maybe once or twice a month if I’m lucky. Sometimes we go a month or more without being intimate. I’ve asked him before if there was anything he wanted me to do that would be more of a turn on for him like if I should wear lingerie or some thing. He said no he doesn’t want anything. And he told me that he still masturbates occasionally. Which was pretty upsetting to find out because it makes me feel like he would rather go self pleasure then be intimate with me. And it’s not like I am an unattractive person either. I’m in my 30s and in decent shape, I could lose a few pounds but I still look good. My partner is also semi self employed so his schedule is pretty flexible but he is just work obsessed. It’s like he would rather be working and doing research for work then spending time with me or helping rebuild the relationship. I try to get him to do things and spend time with me but he would rather work. I don’t know what to do anymore I feel so stuck