Sorry if this isn't what you want to hear, but this really stuck out for me:
"I have tried medication but I can't not get over the initial horrible side effects which just feeds my anxiety and health anxiety and makes me feel so much worse."
I was exactly the same for years, I took citalopram and completely lost my appetite, felt sick and generally felt dreadful - and gave up after a week.
I've been having CBT, therapy, all sorts, but not really getting any better and really struggled to function in work and in relationships. I had frequent panic attacks.
When I went to the doctors in April they suggested I tried medication again. What they said was that though I was hesitant, ultimately what I was doing wasn't working. If I really didn't get on with the antidepressant we tried then we could come off it and try something else. I wouldn't lose anything by trying.
So I agreed, and honestly it's the best decision I made all year. I feel so much calmer and able to think through things clearly without the constant cycle of worrying and panic attacks. For the first week I felt quite sick and had some stomach problems
but really, it wasn't that bad and I just had to push through it. I appreciate that if you have health anxiety then it does make it harder, but maybe you could agree with your GP to meet with them after one week to go over the side effects.
Please give it a go - it's honestly changed my life
and I am continuing to have CBT type therapy to learn how to handle things better. Since I feel better overall it's a lot easier to focus on learning those skills.