Falling out of love

We go for weeks without having sex. When we do spend time together he is busy on his phone or will just fall asleep. He's out every weekend. I'm usually stuck in work. We have been together for 4 years and I just feel lonely, quite worthless and trapped. I've spoken with him about ending our relationship but for some reason he wants to stay with me, maybe because I'm just convenient to him. Will this feeling pass ? What do I do?