You can breathe. Just concentrate on it. Slow, deep breath in, slow release out.
I absolutely know where you're coming from. My H is rushing me into a D I never wanted. The more I tried to fight him, the worse the situation got - so I just stopped. Stopped speaking to him, period. All communications have to go through L's. I was not in any emotional condition to deal with it. I'm still not, which makes me even more grateful to have a L representing me.
This situation is awful, but don't let it beat you. Spend 10 minutes just breathing. I'm serious. Stress tightens up everything, and it makes it hard to pull in a deep breath. You have to concentrate and make your lungs expand. At first, it's going to feel awful, like you're suffocating. In a sense, you kind of are. It is the best thing you can do to calm down, though.
Stop everything for 10 minutes and just concentrate on breathing. It doesn't mean the end. Really. Just breathe, okay?