Sleepless Nights

So Molly started sleeping through the night when she was about 6 weeks old. It was heaven. However, she is gradually waking up more and more. when she hit about 4 months old she started waking up a couple times at night. I figured she was just hitting a growth spurt. I thought she might not be getting enough to eat, so that is when I started feeding her cereal and other foods. It seemed to help a little. Then she became really fussy around 5 months. She constantly pulled at her ears (until they would bleed,)so I instantly thought she had an ear infection. So I had the nurse at work test her ears and they were fine. So my next thought was the dreadful TEETHING. I bought the baby oral gel day/night, and the teething tablets but that still didn't help her sleep through the night. At that point I ran out of ideas. I don't think she was teething because she still has no teeth, but I have no idea what her deal is. She is just over 6 months old and she wakes up constantly. Like last night from 10:00 pm to 1:00 am, she woke up every 20 minutes screaming. I would just start to doze off and next thing I know she'd be screaming. Finally she slept from 1:00 - 4:30, then she was a wake again at 6:30. I decided I needed to start a strict routine. I thought I had a routine but I realized it wasn't happening at the same time every night. We are horrible at getting her to bed at the same time every night, and I know we get her to bed pretty late (9:30ish) but when Aaron doesn't get home until 7, and by the time we eat dinner and go to the gym it is 9:00. I am desperate at getting Molly to sleep through the night again so tonight is the first night of our "strict" routine. I feed her and give her a bath. Then our favorite, we lay her on our bed for about 10 minutes and play. She gets very giggly when she is tired. (I will post a video later.) I then fed her and get her to bed by 8:30. I hope she will get sleeping through the night again, it is so hard to function on little sleep. Wish me luck!