It's important to remember that there are thousands of other students across the country going through exactly the same thing as you. And, even if the worst case scenario happens and you fail or don't do as well as you hoped, you still have options. You can take some time off and apply as a mature age student or you can do a bridging course and get into uni. It's not the end of the world. So keep your chin up, don't panic and, as a famous fish once said, just keep swimming.