Hey Melissa, it is good to have you on board. You can do this! Start today and make one change; that might help it be not so overwhelming.
For example, you could start by logging in what you eat, or cut out a nightly dessert, or do just ten minutes of some sort of exercise (you sound like a really busy mom with the two little ones, but ten minutes is enough to get you started). Or have fruit for a snack instead of what you might usually eat. Just take it one step at a time...if you try to overhaul everything right away it will be too difficult to stick with. Once you have a new healthy habit established, add another one.
Keep your food intake pretty consistent across days, too. From your description, it sounds like you deprive yourself in efforts to lose weight but then it rebounds. That's your body's way of telling you that it's not working.
You can put your info into FitDay and it will tell you how many calories you should shoot for daily in order to lose weight. Shorting yourself doesn't do you any favors.
Hang in there and take care of yourself. It is time for you to do something good for you! Keep us posted!