Over Sensative Hearing

Hi all,

I've struggled with anxiety and depression now for about 7 or so years. I recently worked up the courage to see a Psychiatrist who diagnosed me with Panic Disorder and prescribed me 100mg of Zoloft. I later decreased down to 50mg (which I am currently on) and things are a bit rocky, but nothing like they were. One of my biggest triggers is anything that involves my health or breathing. But lately I have been having this weird symptom of anxiety that I can't quite figure out what's going on.
While I generally take steps to decrease my overall daily anxiety, every once in awhile out of the blue something will catch my attention via my sense of hearing. It becomes a nuisance and often times feels like it's a hallucination. When I thought I was hallucinating I was thrown into a deep panic and thought I was going crazy. After this happened a couple of times I would try and figure out what the noises are. Sometimes it would be the humming of a the refrigerator, sometimes it would be the vibration of my phone 3 rooms away, just recently it was this god awful humming noise coming from a soda cooler at the local retail store. I know that I am not hallucinating since I asked my SO if they could hear the noises, and they could.
Now that I have tackled that part of my anxiety my mind continues to play tricks on me and it causes me extreme anxiety. It usually happens at night when I am trying to fall asleep. We sleep with a window AC which is pretty loud and drowns out most noise but every once in awhile I will almost fall asleep and some random noise will wake me out of almost sleeping and I will lie awake in anxiety.
I guess what I am looking for is someone else who experiences these sorts of things and what I can do to let go of these noises I hear. I've tried deep breathing and focusing on the sound of my breath but it's almost like the noise that is bothering me gets louder and louder until I acknowledge it.

Anyone? Help!