My son turned 5 months on the 17th. He had been sleeping 11 hours at night (occasional waking but would suck his thumb and go back to sleep pretty quickly without fussing, just a moan or two), and was taking 3 naps (35-90 minutes) in his crib (we'd go up when he started looking sleepy and sucking his thumb, he'd suck his thumb and listen to white noise and be down in minutes). We went on vacation last week and he cut his 2 bottom teeth. He was a little thrown off by being away (night waking, not napping in pack n play but napping on bed with someone laying next to him or being held) but was still generally happy. We came home Saturday and he took a great nap in his crib but since then he has been waking around midnight and 3am like clockwork screaming and crying and needing to nurse back to sleep (only nursing less than 10 minutes). During the day he screams and cries when we get near his room or he hears his usual white noise (waves) and loses it when I try to rock him like I used to to get him down. All of a sudden he also doesn't seem to be sucking his thumb. He won't go to sleep unless I nurse him and I am trying desperately not to but he gets so tired and is screaming and crying endlessly until I let him nurse. I try moving him into his crib but he wakes up and becomes upset and also is getting very little daytime sleep now. I don't know what to do but I can't handle him crying, it's breaking my heart. He was he happiest, most content baby until now. Any advice????