I’m not always comfortable with the advice that friends give because they don’t have the training or the experience, and they don’t have to live with the consequences. Professional counselors tend not to give actual advice, but rather lead their clients into making a decision for themselves. That said, there’s no way that I could tell you whether or not you’re “crazy” for staying with him. There are so many factors that go into making a decision like that. For example, how is the relationship as a whole? Your sex life is in bad shape, but has the relationship as a whole deteriorated?

You’ve invested 11 years with this man, so my advice would not be to throw the relationship away without working on it a bit more. You say he won’t get help, but sometimes if one party goes for help, the other follows, even if reluctantly. I assume you’ve asked him about this change and he’s not telling you, but perhaps he’d open up to a therapist because there is a reason and he knows what it is. I’m not saying that I guarantee that seeing a therapist will save this relationship, but I do believe that it would be worth the effort.