Use this as a life experience to prepare you for other things in life that won't work out on your first try. Would be great if you knew the reasons why you didn't make it this time but even if you don't, it's good to realize that life doesn't always go as planned. So we come up with another plan. If you really want to go to graduate school or feel it will be helpful for your career, then definitely try again, but whatever you do, be proud of what you've already accomplished and excited about the future of unknown possibilities. With every good wish!