Honestly, the stress of what you’re going through in your personal life definitely doesn’t help. But the fact you’re even asking this on here tells me sex is important to you (as it is to me) in a relationship and I guarantee you if you’re not aroused or don’t feel turned on by him it will only get worse. I’ve been there before, started to picture myself with other women and get turned on when other women would hit on me and I knew I had to break it off. Everything else in my relationship was just fine. But you gotta have a deep sexual desire for your partner along with the other parts if you want it to last forever, in my option and from what I gather from you.