Hi there Daizy
You already love to work out. So instead of finding time... make time.
You don't have to take time away from being with your kids. Make them a part of the fun as much as possible. Even going on walks with them is spending time with them as well as moving.
You may have to 'force' yourself to do some sort of exercise video once they get to sleep. Or you may have to get up earlier in the morning (I know, it doesn't sound fun, but if you
want to exercise, then you must do it when you can).
If you want a cheap & easy way to track your food intake, I suggest Calorie Counting. (Go to the Calorie Counter's section under Diet Central for more information.)
Make your health a priority. Not just for you, but for your kids! They'll appreciate in so many ways having a Mommy who can keep up with them and who takes care of herself
Best of success!