30 month old having trouble sleeping?

We need some help, my oldest son use to sleep with no trouble. We could lay him bed after book time say our prayers and leave the room and he would sleep Though the night. After a trip to the Midwest, mommy returning back to work from maternity leave and a surprise removal of a pacifier this is no longer the case. Now he takes a little longer to initially go down which is fine, but he will wake though out the night crying and screaming for mommy. If I dare go up he is very aggressive wanting to hit, spit, slap, and bite me. She can get him calmed down and back to bed for another hour if we are lucky but he is soon to rise with the same effect. I have no idea where to go with this. I am hoping it is just a phase but so far it has been pretty painful for me and my wife plus we hate seeing him go though this.