By "benign vertigo," I assume you mean benign positional vertigo. That's what I have. It comes and goes. I'll have it for a few days or a few weeks when I lie or move in certain positions, then it goes away for a few months, then comes back. It's annoying, but not serious. It's caused by crystals in the ear that roll around in the wrong place. Sometimes you can get relief by leaning forward and rolling your upper body in one direction or the other, thereby shifting the crystals. Eventually they disintegrate or dissolve or whatever, and that's when it goes away for a few months.

I get irrational fears sometimes that I'm going to have a heart attack. I'm terrified of having a heart attack, so I worry about it a lot. All I can tell you is to try to focus on other things, find something to do, get your mind off it, if you can find a way to do so. I'm not a doctor, but if you had a brain tumor, you'd probably have a constant severe headache as well.