I don't have any advice, but I'm in a similar boat. Any time something feels different in my body, no matter how small, I automatically always jump to worst case scenario. Seems like every day is something new. I'm sorry I can't offer any support other than to say, you're most definitely not alone. I hope we're both able to find peace.
I'm going through it too having heart palps it's scary. Why does this have to happen to us?
Blood work to check vitamin D, RBC magnesium, vitamin B12, iron/ferritin.
Deficiencies or low normal range can cause fatigue, body pain, muscle weakness, vision problems, rapid heart beat, heart flutters, headache/migraine, tingling in body. Etc.
This is health anxiety and you can be better only if you accept you are fine and stop thinking. Keep yourself busy in some work, talk with others, do some hobbies everyday, its all in our mind.
You are fine and fit. Just do as your doctor say, it will help and take proper medication.