How to calm the body down?

Does anyone find their body flares up in a stress response at any kind of deviation from equilibrium? 

Even if good exciting things are happening my body gets triggered and I suffer with (sometimes all but not always all at once) headaches, neck pain, jaw clenching, constant butterflies, cough, hives, IBS flare ups, sleep disruption, eye condition flare ups... I just don’t know how to calm it down. 

I do yoga, I journal, I nap if I feel I need to, I try to say no to social events I don’t really want to go to, I take Xanax as and when I need - I mostly just ride it out and try and take care of myself but sometimes these symptoms get in the way of things I need to do! Any tips for getting the body to calm down a bit?