Why doesn't my boyfriend want to have sex with me?

I have been with my boyfriend for 10 months. When we first got together we had sex just about every day. Now we hardly ever have sex, maybe once a month and he never Initiates it it's always me. He also shows me no affection at all. I have begged him to show me that he loves me to the extent that tried to kill myself and then a couple weeks later ended up in th hospital for two and a half weeks because I was so devastated because I felt like he didn't love me? I have cried my eyes out day after day to him and it's does not mater how much he hurts me, nothing bothers him. We have talked and talked about this situation over and over again for the past 8 months and nothing has changed. He constant ing saying he will try harder to show me that he loves me. He has started giving me a peck kiss each day although we still have only had sex once in the past six weeks. We both suffer from bipolar and are on medication? We both go through bouts of depression and have to deal with side effects from our meds. He tells me that he nosexual libido because he is never horny and then has a hard time getting an erection