This is one I've battled with all of my adult life, and there are no easy answers. In your case it seems to me that your body has reacted totally normally to a decrease in your exercise and increase in calorie intake.

I try to think of it in these thermodynamic terms now, though it's easy for my body image crap to get involved. I can recommend The Hacker's Diet (http://www.fourmilab.ch/hackdiet/www/hackdiet.html) *not* necessarily to lose weight, but to help you focus on how your weight is effected by energy intake and output. It's working for me.

Those are my thoughts - you are entirely free to ignore them :)