I also cannot avoid working less than 50 hour weeks (usually more around 55). I think focusing on making sure I am spending the rest of my time doing positive things that contribute to my life is an excellent suggestion for meeting this goal!
How to stress less
It made me
feel as if I can fly 
"a weight fell off my shoulders"
How I did it: I was really determine to have less stress in my life - and more fun. At first, I seemde to have chosen the worst moment there could be: a period where there was no hope of working less than 50 hours per day. But the key to everything was discipline and living in the very moment. In the morning, I took some time either or sport or reading, in the evening for meeting friends, sport and other personal hobbies. I also made a to-do-list of items I had long put off, then decided whether I really wanted to do them. If so, I did them asap, if not I crossed them off, considering them as "done" nonetheless.
Having pursued this strategy for 2 months, I can say that I am less stressed - and have learned a lesson for my life!
Lessons & tips:
- make a list of things you need to do
- complete the necessary work conscientiously, always concentrating on the thing you are doing
- reserve some daily time for personal hobbies, interests and dear people
- complete all those things you have always postponed - or decide to forget about them once and for all
