Anxiety especially at night

Hello everyone, I am going through a terrible state of anxiety at the moment which I am at a loss as to how to deal with. It all started with pulsating tinnitus which started in November. I think this was due to either a sinus infection or going to a music concert! During the day I cannot hear it unless it is very quiet. At night it is dire and has given rise to massive health anxiety. I have had panic attacks, been awake most of the night and am now resorting to having to take either a sleeping tablet or Diazepam and am unable to control my anxiety.
I have been referred for an ENT opinion which is next week but although this will help I think this appointment will only be the beginning of a path of investigations. I have also managed to get myself on the nhs waiting list for CBT counselling which is also a positive move. My doctor has prescribed Mirtazepine to take at night. So far I have not been keen to take this for 2 reasons. One is that most reviews mention that they increase your weight, although this seems a fairly shallow reason not to take them, I spent 6 months at the end of last year losing half a stone which was a struggle for me and I don’t really want to repeat and secondly I was worried I would get addicted which would cause state of anxiety! I have become somewhat of a worrier as you will probably gather!
This is blighting my life (and my poor DH) at the moment and I need to get things back into perspective. Any suggestions gladly received.