Pregnancy can trigger thyroid (and other) problems - so it would be good to talk to your doctor and get that checked out. Also if you are not sleeping 'normally' (I don't even know what that is anymore! lol) or if you have postpartum depression - you will have trouble loosing weight and can gain weight. I had that problem with my first (but not my second). Also, write down what you are eating - in the new mom daze, I have often scarffed somthing down and not even realized that I had eaten anything at all. (and blamed my husand for eating my treat!)
I have on occasion hired a 'mother's helper' - basically a teen from our church comes and entertains the kids while I do some exercise or cleaning or meal planning for 30 minutes to an hour at my house. Sometimes thier mom comes over and helps so that the kids can get babysitting experience for thier resumes.
You could make some small changes to what you are eating - like if you normally drink pop or have tea/coffee with sugar and cream, you could cut back or replace that with water, if you have chocolate or cookies in the house and mindlessly munch - you can stop buying those things and switch to healthier options. Planning your meals is a good way to not resort to eating whatever, and you have all the ingredients to make things that are healthy if you plan ahead. Small changes made with consistancy over time lead to big results!
I hope some of this is helpful. You can do it!! Let me know what you find works for you!