Been under a lot of stress in the last 3 weeks I have not been sleeping well at night?

Try Relaxation. And Deep Breathing technique. Exercise in whatever form you like. Try talking to some one may be a friend/family or counselor/priest whom ever you trust.And try to focus on one thing at a time, do not think about too many things at the same time. Listen to soothing music at night. NEVER THINK ABOUT HOW TO SOLVE PROBLEMS AT NIGHT. This too shall pass.