So many "what if's" and "could be's"

If there is one thing I am realizing as a new mom it is that there is nothing about parenting that is set in stone. Every child is different, and every parent reacts differently to different situations. While I know this is true, I think that listening to other people's opinions helps to educate me to make the best decision for me and my daughter. That being said here is my first question/situation: My daughter is two months old, and for the last month and a half, my daughter has been sleeping in her own room. It took a little work to get her there, but it was going pretty well. She had even worked up to about 7 hours between feedings, and that allowed me about 5 hours of solid sleep a night. That was until about a week ago. First it started with her just suddenly waking up, and screaming like she was in extreme pain. I would run into her room, pick her up, and she would go from screaming and being stiff as a board, to sleeping and limp in less then a second. Every time this happened I thought it was extremely weird, but I would just put her back to bed and go back to sleep. Then three nights ago, she started screaming and wouldn't stop untill I was holding her. Every time I thought she was asleep and put her down she would wake up and start screaming again. I finally had to bring her to bed with me so I could get some sleep. The night before last the same thing happened, but my husband was home (he works nights), so he took her, but still, she screamed until she was back with mom. So last night, I left the light on in her room so that maybe she would think she was just napping downstairs where mom is, like she does during the day. She didn't wake up screaming once. However she woke up to eat every three hours, just like she does during the day. It's like she's reverted back to her newborn sleeping schedule. Needless to say, I have no idea what to do. I don't know if she's scared, or just thinks she needs to be with me all the time. I have to go back to work in 3 1/2 weeks, so I'd like to figure this out before then so I can actually be somewhat rested at work. Anyone have any ideas?