Suffering from ppd with a 3 1/2 month old but has baby fever really bad

I've been suffering from baby fever for almost two weeks I've had non stop depression over it and can't stop crying my daughter is only 3 1/2 months old but I want another baby now but I have to wait until I graduate and that's in two years I've tried everything to stop it and it's not working and I'm on depo provera I know it's side effects but I wish it was pregnancy