The boyfriend does not sound like a catch. Your life sounds like it would be immensely simpler without him.
Take a break and work on making things simpler and more comfortable for a while. Talk to your husband, even if there's no hope for romance. Keep the communication open and as civil or even friendly as you can. If you can reduce the complications and clutter in your life in other ways, you might try it. Find or make some room in your life and your headspace to think and process things, instead of reacting.