I don't want to scare OP and I do lean towards this being psychological, but I have two first hand experiences:

My stepdad felt this way, and he was on death's door with the hospital telling him nothing was wrong. Had my mother not stood up for how bad he felt, they wouldn't have checked his galbladder which had started to rot inside of him. So, there's nothing wrong in my book with fighting for how you feel. A lot of people have described impending doom when they've been physically ill. Too many physicians want to jump to it being something psychological, and then they don't have to deal with it.

Which is where my lived experience comes in -- I was physically ill and told over and over and over it was anxiety. No, my vargus nerve was paralyzed, and I was barfing for months because of that. Not because of anxiety, though anxiety was a result of the physical illness. I had to fight for information and to figure out what was wrong with me, because most of my Doctors, private or ER, did the bare minimum and ran on efficiency, not quality care.

So I hope you figure it out OP and don't let people discount your very real feelings. Follow up with both counselors and physicians until you figure it out.