K.Z.
S.,
Don't do any serious dieting as you described. You have lost about 2 lbs/month, a very safe pace. "Pump-to-dump" is a big hassle for you and the baby. Remember that formula will cost money too.
You could try just the stage 2 diet and see how that works.
Someone named Susie has posted diet advice before from (I think it's her name) Dr. Sandy somebody in Columbus. The basics of the diet are to eliminate dairy, wheat and sugar. When I do this it is a lot easier to lose weight, I don't feel like gnawing the table legs off from hunger.
Also try to get a little exercise every day. Even a walk with the baby in a stroller or sling would help. Get adequate sleep too (I know, easier said than done).
Good luck!
K. Z.