easily disturbed/sleep concerns

Hello everyone. My son is now a health,huge 3 month old (17lbs). Recently he
has become a very unsound sleeper. At night I will nurse him to the point where
he is so full that he keeps jerking his head away in frustration because he
wants to comfort suck but doesn't want anymore milk. I've tried pacifiers of
all different types but he won't accept them. He usually begins to cry and
scream so I pick him up and rock him to sleep. When I lay him down in the bed
(we co-sleep) he begins to squirm and move about an hour later. I've tried
waiting to see if he would settle himself back to sleep but it always escalates
into a screaming fit. This pattern is often repeated in hourly intervals
throughout the night. If I catch him when he first starts to move around and
latch him onto my breast he will suck for a minute or so and fall right back to
sleep. If I don't, however, he gets to the point where he must be picked up and
rocked back to sleep (this can take up to 30 minutes, and of course makes me
feel horrible).

I will say that he usually does have a stretch of sleep from about 9 PM to 12AM
in which he doesn't wake up. Any advice or reassurance? It is just so
frustrating b/c I know he is developing a strong association between sucking
and falling asleep. I hate to let his crying escalate into screams and trying
to wait them out to see if he actually settles himself back to sleep is pure
torture (and doesn's seem to work).

~Tracy