Sometimes fears get the best of you in dreams, Some have a fear of drowning or falling or whatever it may be. In your dreams it is the one time you can over come them. As everyone said before, you have to start to realize this is my chance to overcome my fears and make them into what you want them to be. Instead of dying think of things that can save you. For instance a boat comes to save you or the shore is close enough to swim too. Start small then learn big.