I find pain a way to relax. By that I mean sharp pain. For example, I am a hopeless procrastinator and then because I have left things until the very last minute I get really stressed and can't think straight. So I found that sharp pain can help me focus.
So one way is I put nipple clamps on my nipples (obviously). It's kind of like totally focussing on the pain helps clear my mind. Then there is a tightening across my chest and I enter this state where I set myself a goal to start or reach a milestone with whatever is stressing me. I have to do this before I stop wearing the nipple clamp and if it stops hurting I reposition it. I have even work them at work while doing a presentation to management that I was really stressed about.