How can I get over my nosocomephobia (fear of hospitals)?

When I was 7, my mom and I were visiting my grandma in the hospital. While in her room, I literally saw her flatline. It was THE most depressing and terrifying experience in my life. After that, I have been terribly afraid of hospitals. I always feel like me and or my loved ones will drop dead suddenly. I always have this feeling that death is right around the corner in hospitals. A couple of weeks ago, I had an appointment in the hospital. I had to see what was giving me headaches. My parents had to force me to go in there. I was crying hysterically. I was getting breathless, and my heart was beating faster and faster. I don't want to be this way forever, because something really bad could happen to me and I would have to go the hospital. With this fear, I might make the mistake of my life by not going in them!