Stress definitely makes things worse, but I believe part of that is somatization. I have severe PTSD, so at times my panic attacks or emotional responses trigger my fibromyalgia pain and migraines. My social anxieties also trigger migraines. Generally speaking, any stress causes me difficulty even eustress (positive stress like at my wedding; I was happy) and can trigger pain, exhaustion, and migraines. The exhaustion may or may not be in the realm of "normal", but being so happy you get a migraine definitely isn't.
I've been working on tackling stress through a few techniques. The first is organization. While I don't have this down yet, the more organized and planned out things are the less stress I have. I don't lose my keys, for example, because I put them on the same hook every time I come into the house. I know precisely where they go, and that's one minor annoyance off my back. The same goes with mail and other small routines.
In addition to organization I have worked on some mindfulness meditation and Tai Chi (which most of us could handle some of). It helps you center and focus yourself and allow the stress to leave without doing as much damage. This can also be accomplished through most creative hobbies: writing, art, music... anything that engages your creativity. Even if you're working on building a car (which is definitely creative) or doing a puzzle of some kind that counts. It allows you to focus the conscious part of your brain on something while the unconscious process the stress response.
In moments where I'm having a panic attack or am otherwise under extreme stress I turn to breathing exercises - they give me a few moments to focus deeply on something and try and soothe my body's panic response and get my heart rate and mind under control. I've used it to great effect after car accidents, during and after severe injuries, and while handling other people who are injured, frightened, or otherwise in extreme circumstances.