Baby sleep.. Help!

Alright ladies, I really need some help!

My daughter is 5 months old and out of nowhere she is having the worst time going to sleep and staying asleep. She wakes up every 1-1/2 hrs at night and refuses to go back to sleep.. I've tried feeding her, changing her diaper, rocking her, giving her a bath, letting her sleep with my husband and I, white noise, Tylenol, even watching TV and playing in the living room to wear her out.. She just cries and is very upset.

During the day she constantly whines, cries and yells but nothing helps her. I'm assuming maybe she is teething or something? Is there any tricks that I can try to help her??