Sounds to me like a bit of paranoia creeping in. I do agree with mujer that fear is often associated with anxiety/depression but that fear becoming overwhelming is the start of paranoia. If it has only started developing more recently I would be talking to your pdoc about it and seeing if you can see any correlation between the feelings and recent med or other changes. Might be worth tracking the way your feeling and taking that along to your next appointment as well.

Stay safe and I hope you find an answer soon. Sounds like what your going through is no fun at all.

Hugs