I agree with the exercise. I was pretty much having regular meltdowns until I started to exercise. Aerobics yes, but IMO, resistance made a bigger difference.
I also try to remember something a counselor once told me. "We overestimate the danger, and underestimate our ability to handle it". I try to think about that when I am starting to stress.
One more thing. I once read that the very best thing you can do for your health, is have at least 2 or 3 close relationships, and connect with them several times a week. Talking it out, trying to find the humor in most situations, really helps.