Why do I have suicidal thoughts?

I know I could never kill myself, but I find that when I am alone and still my thoughts tend to wander to suicide. My life isnt bad, I actually have a loving family, a job, a house, a car that runs, and a loving husband. I just don’t know what is wrong with me. I probably would kill myself but the catch 22 is that I am incredibly scared of death. I think about it all the time and I cannot cope. I have seen doctors and try to rid myself of this fear, but the fear itself is taking over my life. For instance when I’m driving or lying in bed I always am thinking I wonder if this is the day its going to happen, and think of all the ways I will die, ect. I dont know maybe I’m just hear to vent or maybe there is someone out there who may have been where I am, anything would help.