Good for you two for trying to change this dynamic. When fighting, the goal is to "win." In the process, you hurt each other, and you both lose.

Some general advice: Since you see the pattern, you can make a plan about how to handle the after effects of therapy. You can figure out what you will do to self-care (bath, jog, art, nap, whatever). You can figure out what you can do together. Have a plan in place for how you will approach turmoil, and try to stick to it when the time comes. If he is busy, do self-care, or call a friend.

My personal advice: avoid doing two emotional things at one time. If you are upset from therapy, try not to troubleshoot your relationship at the same time.