Back at it again...

My baby is now 6weeks and I can start to exercise again. I'm the biggest I've ever been and need to drop som lb's fast to get motivated. Last year at this time I was doing so well but now I don't even know where to start!! Can't really do the daily gym thing because they don't do daycare with children this young and it's getting a little cold for walks....I really need some suggestions pleases!! Any diet pans that can get my ball rolling??