My stress based disorder is cluster headaches and they literally feel like death and all I can say is don't rely on doctors to help, diet changes are not in most western based docs playbooks, drugs which cover up and masks the problems are, try heavily modifying diet, start going into ketosis and see if you feel better after a couple months. It took me 8 years and the best healthcare around to reach this point. Cold shock seems to quite stress/inflammation as well. These things are freely available.

Other non drug alternatives: Meditation, acupuncture, camping, horse back riding, walks, runs, swimming all seem effective at lowering stress as well from my exp.