I wish I knew what to say that could be helpful. I've been doing this therapy thing with current t for omg 12 years now (with breaks from time to time, the longest of which lasted a full year) and I still laugh while talking about certain things (that are decidedly not funny) in therapy for me it's absolutely a defense. Like if I laugh, I don't have to feel. I laugh so I don't cry. Which is odd because I cry so easily about lesser things.
Therapy is hard.