I had PPA and definitely experienced parts of what you are describing. Even though I consider myself "through the woods", I still check her breathing every night. I was also OBSESSED with her health. I kept thinking things were wrong with her, even though she is perfectly healthy.
OCD can be part of PPA.
I definitely think losses can play into it (I have had 2). I think it makes us realize how quickly something can be taken away from us.
I would suggest seeking a therapist. I know it was integral in getting me back to myself.