How do I get over my fears of dying?

Recently, I had a close call after delivering my second child (blood clot followed by internal bleeding and several blood transfusions). It was a close call. I am currently undergoing medical treatment because of the event, and I am constantly afraid the whole ordeal will happen again. I have never really had anxiety in the past, but I find now that it consumes my every day and night. With two beautiful children to raise, I am most terrified of not being able to raise and protect them.