DS is 12 weeks old. He was sleeping 4+ hours his first stretch at night and 3 hours after that. Ever since his shots, his sleep has sucked!! He'll sleep maybe 3 hours the first stretch and then is up every 1.5-2 hrs after. If he wakes at less than 2 hours I put the pacifier in and can usually get another hour out of him. 2 hours and I go ahead and nurse. How do I get him to sleep longer stretches again?? I'm going back to work in 2 days, I don't know how I'll work 12 hours after waking up so much at night!!

Fyi: we swaddle him with a halo swaddle sleep sack (which he usually gets one arm out of when he wakes up) and he sleeps in his crib in his own room. We have a pretty good bed time routine of bath, massage, nurse (usually to sleep) and when I put him down he will usually stir but go to sleep (although that has been less successful too), same with nursing in the MOTN (falls asleep but wakes/stirs when I put him down, having more problems of him going back to sleep sometime too). He usually takes multiple 30 min cat naps during the day (in the swing). Bed time routine starts about 830pm.

HELP!