However, over the past year I have lost 10 - 15 pounds and am unable to put it back on. I am currently eating 3 meals a day and taking a protein supplement. At the beginning, make small increases every workout, because at the beginning, the body adapts quickly. Don't just blindly push yourself. I have noticed a difference, but I have put on about 3 pounds.
Muscle weighs more than fat.
If you've put on a couple of pound of muscle, that's a good thing. I like to stay very basic. Spread your caloric intake out over 5-6 small meals instead of 3 large ones. Get one of those carriages where you can run with the baby 3 times a week. A banana for snack at 11am.