Welcome to PC

Sounds like the start of walking on eggshells with your partner. His snide comments are uncalled for. Quite the imagination that he's got going on for himself.
I've been there, done that in that aspect. It didn't work out in the long run. The more I would try to soothe/reassure, the worse it would get. It did eventually turn physical.
There was also some addiction issues with mine going on, is that also the same in your situation? Down the road it was discovered there was a personality disorder on top of that. I hope that isn't the case in your home? Panick attacks? Is it only heart palpitations and shortness of breath or are there other symptoms?

Hope you find the support that you need.