Exercise
When stressed the body experiences a build up of tension and toxins from the fight-flight response. The natural reaction when experiencing fight-flight is to move -generally to run away or fight. Most of the time when we now experience f/f we do neither.
Consequently, the body carries the build up of f/f patterns throughout the day. Working the body naturally with exercise will help release these tensions and flush the toxins out and create beneficial brain chemistry helping towards a calmer mind and better sleep patterns.
Don't add more pressure to your schedule by putting in too many things -even exercise sessions. Work to incorporate exercise into what you do daily. Park 15 minutes from work and walk in or cycle, walk up and down stairs instead of using the lift, have an office rebounder, etc. Good stress releasing exercise would be walking, cycling, swimming, yoga, Tai Chi, and rebounding. Basically all non-stressful aerobic activity is helpful. Do regularly.