I work with a lot of women. And I can't name one who doesn't have a complicated, if not down right negative, relationship with her body. For a lot of postpartum women (the postpartum period lasts forever!), the connection with the belly seems to be the one wrought with the most contention. For some it's the thighs, or the butt, or the arms, but there's always something.
Here's the thing about the parts of our bodies that we don't connect to in a positive and loving way: they need even MORE love than the rest of us. So try this simple exercise sometime today, and see how it goes. Then do it again tomorrow, and the next day, and the day after that. Whatever part(s) of your body are giving you the most stress or anguish right now, find a time in your day to touch that part of you with extra kindness. The shower is a good chance to do this, but whatever works. Massage your belly, or your thighs, or your boobs, or whatever, with some nice smelling oil, or a lotion that just feels good. If you can't find time or head space for that, just gently touch that part of you and send some loving vibes. Whisper something nice to that part of you (either silently or not) and see what happens. Healing never comes from hate, but it can come from love.