The way I see it, you and your husband are cooperating in this argument. Instead of dealing productively with whatever the issue was, the two of you got completely distracted and derailed by an argument about what’s fair to bring up in an argument. It makes me wonder what was so difficult about the original issue that you went off on such a painful tangent.
Yes, you have baggage. Who doesn’t? My guess is that you could find something to pin your husband’s defensiveness on. Yes. It’s a betrayal of sorts whenever someone we trust uses something they know about us to hurt us – or to defend themselves. But arguing about that will only continue the argument about an argument. You can react without overreacting. If there’s a next time, simply calmly say something like “I’m sure we could go down that road but we’ve got a problem to solve. Is there something about it that is too upsetting?” Stick with the topic at hand and you’ll find out more about each other.
Meanwhile, I’m sorry that your mother wasn’t able to tolerate any emotional variation in her kids. That must have been very, very hard. As a kid, you couldn’t do much to change it but you can now. I think it’s long past time to refer her to another therapist. You can’t forge a close mother-daughter relationship as long as you take the role of a combination counselor and parent. No wonder you’re exhausted! If your mother won’t go initially, make an appointment for yourself and do some groundwork. Then you and the therapist can invite her to join you. Gradually, your therapist can help you shift over the responsibility for your mom so that you two can start to have some fun together. Wouldn’t it be nice to be able to tell her: “Save that for Dr. Shrink. Let’s go to a movie”?
I wish you well.