That's the spirit. You have the wisdom you need, you just need sufficient quiet of mind to tap into it. When you find you're getting wound up with anxiety, get a chance to take a break, sit, lay down, close your eyes, examine the racing thoughts. Let them race with you as an observer, until they start slowing down and you can analyze them. The rest is pretty much stuff you already know how to do.
We always have a circle of concern (things we'd like to change), and a circle of influence (things we *can* change. Stay focused on your circle of influence -- on that part of it that intersects the circle of concern. Things you can change, that you also want to change. Be at peace about the things you can't change. Rejoice in the progress and freedoms that you do have. Don't torture yourself with things that could supposedly go wrong with M. Instead, rejoice that you have M in your life, here and now. Don't let the goodness of this moment slip away.
Joining a CBT group sounds like a great idea.
Love means never having to say, "Put down that meat cleaver!"