Welcome, Krista. Be sure to have your doctor do some blood tests to make sure you aren't diabetic, don't have low thyroid, things like that. A "shot" to lose weight just doesn't sound like a good idea to me . . . but who knows. I'd have to gather more information about it before I'd agree to it.
Mostly weight loss seems to be about watching what you eat, and for some people that means keeping a food diary of some kind where you actually put down everything that goes into your mouth. It's quite revealing about food habits.
Also, activity is a good thing--but you may need more than just taking care of the house and baby. Do you go for walks with the baby in a stroller? That's good exercise for you and a nice outing as well.
And I also wanted to say, Kayleystar, you are awesome! Go, girl! Keep on doin' it!