Dieting with a baby

So I have been dieting for almost 10 years now, off and on, and since having a my baby it has completely changed.  I have always had issues taking weight off but now it seems to be different, harder!  Also, I find that they weight doesn't come off where it use to come off of first.  I have never had a lot of energy but it seems like now I am lucky to make it through the day, though when it comes to bedtime I can't seem to fall asleep.  I don't understand these changes but I am really hoping that it isn't something that lasts forever!  My son is just over a year and still gets up occationally at night but even on nights that he doesn't get up I still find myself awake! Which may be another reason for my difficulty with my weightloss. 

It just seems as though my body has changed so much and not in a good way.  I would like my old body back and hope that once this weight is finally gone I will have it back!!