I am so sorry you are going through this, it is no fun. I have had episodes like this, they all started after a fall down a flight of stairs, that was over 40 years ago. I had every test known and all that was ever found was unstable blood sugar and numerous food allergies, also weak adrenal glands. My doctor recommended that I see a chiropractor as neck misalignment can cause these issues. Well, I had been seeing one but I went to the one my doctor recommended, I explained what was going on, etc. He gave me some adjustments and I did start to feel better, to this day, if that particular vertebrae is "out of alignment" I will get anxiety. So, between the treatments from the chiro and the herbs, vitamins, etc from the doc, I slowly got better. I will say, however, that I still have issues at times with the anxiety, but it usually is brought on by extra stress. I would sure talk to your GP about this and ask for a thorough blood work panel,make sure that thyroid functions are included, or, see a good naturopath, that is who I saw back home in the states, I wish they had good ones here in New Zealand.
Also, I hesitate to say this, but it is possible that the vaccination could have brought this on. They are so new, no one really knows what kind of side effects they can cause even many months down the road. Sometimes if a person is vaccinated after Covid, they can have a harsher reaction due to the fact it is like "double dosing" the virus.
I hope you feel better soon and can get this resolved, anxiety attacks and the symptoms are a living hell.
Gosh, I am beyond sorry to read about the hard time you are going through. I agree with liuyiacmt. Try NOT to focus on such terrible thoughts as that will only lead to more anxiety.
Have you been to a doctor? You need to go and get a physical describing what is going on.For them to rule out any physical health issue. After that, if they do not uncover anything, to me? You sound to have hit a wall with mental health and be in overload. Perhaps you have long covid which is linked to this. Or perhaps you are like my son where everything mental health wise all converged into a major pile up. Mental health issues do not need to be caused by anything dramatic, traumatic or particular. They can just happen.
Mental health issues ARE treatable. You just need to know if that is what is going on here. You list your symptoms but not what any doctor has said to you. Can you let us know what you've done to work on the why's of this?