I would like to add more to my original comment. Yes it is shitty your lover is selfish, No you didn't walk into this thinking: "Hey this guy is so selfish in bed and that does everything for me." who the fuck would think that? I'm not trying to minimize how soul crushingly awful DB can be nor am I trying to minimize how prosaic a path living with a DB leads you down.
However there is something I often find missing in the threads here on DB and that is personal responsibility. I don't know how many times I've read: "I haven't had sex in whatever amount of years." and my first thought is "Wow I would never have put up with that." And that is exactly what's happening, you're putting up with being treated like crap. You are choosing to stay in a relationship that doesn't meet your needs and it's up to you to maintain your standards and move on when the are not met.
Seriously ... through all of the drama having a spouse with bi-polar disorder like I have can cause i.e. hallucinations, rotating door of meds with varying side effects, a new breakdown every day when I come home from work to the reality of having a spouse that can't hold a job and the inherent financial instability that brings. I can deal with all that shit and still have faith in the woman I love to soldier through to success. But ... I need sex, I need it for so many reasons, and I can't imagine staying in a relationship where my love life was either non exsistant or awful. And me drawing that line has kept my relationship from lapsing into a one sided shit fest I have read so many times on this sub.
Believe it or not your S.O. will respect you more if you draw a line and stick to it, after all if you don't respect yourself why should they?
If I choose to stand by my bat shit crazy wife that is my choice, if that means no sex that is also my choice regardless of the details as to how that happens.