I am sorry to hear of your breathing problems however from the information you have shared it appears you have been to the DRs. several times. I agree with JR, a sleep study may be helpful.
For the dry mouth and throat have you tried a humidifier in your bedroom at night - that helps me as I have a lot of problems with dry mouth.
The symptoms for anxiety go on forever but I will post the link here for you.
Anxiety Symptoms, Anxiety Attack Symptoms (Panic Attack Symptoms), Symptoms of Anxiety:
I am sorry that you are going through such a rough
time of it right now. I know how frustrating anxiety and its
symptoms can be...so I hope that by reaching out here, you can start to feel
some support and relief.