Almost everyone today is posting about health anxiety. Most are aged around 20 and all have worries about cancer, heart or brains.
So here's some advice trying to help.
You've talked yourself into it.
The more you feed your anxiety the worse it will be!
The more you write about it, talk about it, think about it, google about it, see doctors about it, talk to friends about it etc
You need to get out of your head and into your life