My biggest motivator is happiness.
When I was drinking I was borderline suicidal, constantly anxious and just plain miserable and a bit nuts. I was paranoid and didn't trust myself. Some of that followed me into sobriety for a time but then I started getting glimpses of happiness and contentment that I didn't recognise and I started developing a self esteem. I guess part of that was that I thought if I could give up drinking I could do anything but also I just feel a lot healthier in my mind. I trust myself now and am able to make positive changes in my life. I couldn't do any of that while I was systematically killing myself with booze.