Love life

Here's the thing I'm married and separated from my husband. The reason we're not together is because he wouldn't stop using drugs. We haven't been together since May. I started dating my best friend after the separation. He's been my best friend for nine years. We've been dating for five months now. The problems I'm having now are I'm not sure if I want to keep my relationship going with my boyfriend. He doesn't work right now so I'm supporting both of us. That doesn't bother me too much. What does is I'm not attracted to him sexually and he kinda grosses me out. I get annoyed with him a lot but if I break up with him he's going to be crushed. I feel horrible. My husband contacted me last week and told me how he's improved himself and I'm proud of him. I don't know that we would ever rekindle our marriage though. There's so much hurt and distrust there. This is a nightmare. What should I do?? I'm feel like a horrible person.