We are passed the 4 Month WF...but now what the heck is this?!?!?

gbaby26

We are going on week 2 of almost every night or every other night my LO wakes up crying at 2:30- 3 am and it almost takes me an hour to an hour and a half to put her back to bed. She then only will sleep for about 45 to an hour then thats it- she will be tired, yet squirming around/up and irritable until 7 am when she starts her day. I am EXHAUSTED, thank god I am a SAHM but I dont understand what is going on. She is 5 1/2 months old....is it teething, her diaper being really soaked when she gets up (should I be using overnight diapers???)? I dont know but it stinks because she was sleeping so great for so long and now this, I felt spoiled that in ways I feel like I am being punished! Hahahh.

Is there a growth spurt around this time as well??