Husband (32M) thinks about leaving after 11 years together, because I can't change my (30F) behavior

I am a very impulsive and in the moment person, I am crappy at planning and organising and I can't really communicate of consider him in my day to day activities.

Every fight we have starts off with something small but if I react I always come up with excuses and I say mean things of threaten him or I start packing my bag to go away.

I've been in therapy for over 6 years now, on and off, not very regularly, but this is not really changing my behavior.. I always end up talking about my feelings or thoughts and I cannot seem to change the impulsive reaction in fights. I thought I might have adhd and hoped for a diagnosis so that maybe it would give an explanation for my disorganized life and my emotional behavior, but again, this is not the big issue, I don't want him to leave and I want to actually do something about it, or I want to know what to do. Basically how do I think before I speak, how do I not get mad before I actually listen. How do I not try to come up with excuses in my head, to just temporarily make myself feel better. I cannot seem to sit through an argument without reacting like a person from a melodrama.

Tldr: my problem for 11 years has been that I react impulsively in fights, hurting my partner, I haven't changed. I don't know how to change that and I don't know where to start or get myself going.