It is hard to accept what happened to you. What those guys did was very violent and graphic. And it was very sadistic. Knowing that there is nothing that could be done to stop them makes it all the more frightening. Being assaulted brings with it the sense that you have no control over yourself or your surroundings. In a sense, none of us do. But being assaulted can bring those feelings very much to the forefront, making you confront them. That seems to make it more real to you. Other people are just as vulnerable, but they may not have had the same experience that you did, so they are not as aware of it.
It may help you to look at ways you are safe now. One of the biggest ways is your knowledge of how vulnerable you are. Since most people are not that aware of it, they are more vulnerable than you are. You now have the knowledge it takes to help prevent you from feeling sheltered again. It's not a knowledge most people wish to have, but it does make you much more in tune with your own strengths and abilities.