It sounds like there are several things at play here. While Bipolar Disorder may be his primary diagnosis, it also sounds like there are relational issues that go beyond that. If he is critical and domineering (wants you to follow his version of how the marriage progresses), that is unlikely to change (without joint therapy). If you do not feel valued - or at the very least, listened to - an attempt to stay when you are unhappy doesn't seem like it will lead to anything but more frustration.
Since your children are grown, it seems like a great time to take stock of where you are and how you'd like to proceed. If he's amenable, it might be the right time to ask him to engage in marital therapy. If not, it might be a good time to engage in some therapy of your own - whether that be with a therapist, or just talking to friends and building up a strong support network. That way, if you decide to make a change, you'll have plenty of supportive people around you. In fact, this last bit is probably a good idea whether you decide to leave the marriage or stay in it. Having an adequate network of others around you will help you reflect on your life and what you need.
Have you asked your husband to go to therapy? Is this something you'd like to invest in doing, or are you feeling as though you'd be happier on your own?
Yes, of course. I'll be available after 9am, Pacific Time. Shall I check back then?
Since I don't have the capability of a one-to-one call (at this point), I'm going to open this up to another expert.
Thank you and the best of luck to you.
If you reconsider and would like to chat via online services, just let me know.
Hello and thank you for using just answer. The previous expert opted out of this question but I would be happy to help you with your question. If you want a phone call, I can offer it to you through the premium service, please let me know. Thank you.