Weening from bottle to sippie! Help!

Ok moms. So I finally put my foot down with my husband (after I have been telling him for 6 months.) we just began the no bottle and rocking before bed routine and we are on day two and she has been crying, no!, screaming for going on 4 hours. Everything I have read says to let her cry it out. We have gone in periodically to try to soothe, rub her back, tell her we are here, going to sleep, playing music, we have sat in there and talked to each other to try and bore her, she is resentless. she has been using a sippie for everything else for over a year so why is bedtime so different??? Should we give up? Please help!!!!! Is this normal??