Just go back to Sleep!

We've had a near perfect sleep record for the past 6 months, at least 12 hours or more, for so long that we have forgotten what's it's like to have sleep issues at all. That all came to a screeching halt about 10 days ago. Madelyn has discovered that there are monsters under her bed trying to eat her judging from the amount crying and the fight that she puts up at bedtime and when she wakes up in the middle of the night. The latest round of teething must not be helping but it's most likely a case of separation anxiety that kids go though around this age, or is it the gas that she's been passing lately? We basically had a three day/night train wreck earlier this week, with one parent being sick and Madelyn fighting us every time she got close to her crib. We've both caught the other parent standing at Madelyn's door at 2:00am, telling her off in a stern voice and trying to reason with her on why she should go back to sleep. This normally does not work and it takes one of us hanging out in her room rubbing her back for a few minutes to calm her down enough to go back to sleep. We are exhausted like we were in the first few weeks of parenthood and so ready for this phase to be over. Lucky for us everything at this age comes in phases, so if things got worse, things can get better with a little bit of TLC.