I can say that since getting my problems under control, my marraige has improved so much and my life is so much better that I am now now controlling myself because I want to be happy. My selfishness tells me to control myself because that results in my being happier.
What you want to convince yourself is your business, but I think the experience of many people here (certainly mine) is that for our own selfish reasons we should control yourself (not just for G-D).