All organisms deal with stress, you are not alone. Mechanically speaking the chair your siting on is dealing with stress(es) right now. It's an internal reaction cause by load applied by external forces. In our terms, it can be your boss, your kids, your bills, something in your world that is putting the hurt on you. It can be physical or psychological, but on an evolutionary standpoint we need it. It is there for that very reason, to bring change physically and psychologically. In the developing and fast paced world we live in we deal with a lot of change. Its about coping and learning to adapt for the better that we thrive through these changes, these stresses (near epic).
I knew a Sgt. in the Marine Corps, who was in Fallujah when shit hit the fan. He was telling me about combat stress and the whole time I couldn't help but stare at the gray hairs on his head (he was 25.) He was telling me about the people he would see that were 22 and looked 30. Combat stress will age you 5 years, is what he would say.
Exercise. Use the stress to your advantage. Throw some weight around. I know a lot of people (not me) who love to go running or biking or even take long walks to keep a clear head and focus on nothing. Maybe cars and pots holes. I take that back I'm a walking type, but I do a lot of thinking while I walk, and it always turns out good for me.