well... for one, you shouldn't be changing his formula around so much... my son went from normal formula to soy and it doing perfectly... he sleeps like a rock and only wakes up when he's wet hungry or just wants attention... we've put a pretty good stop to the attention cry by just checking him (and if he's not wet and it's not food time) and ignoring it...occasionally we give in cause he's just too cute lol... but if one of you has a job and the other doesn't you should try scheduling like this:
(this is what we do)
while my S.O. is sleeping i stay up and he helps out occasionally
while my S.O. is working is stay up as much as a possible
and while my S.O. is home i sleep.
we're only keeping this schedule till our son sleeps through the night
hope i helped... ttyl