When you cannot get over an obstacle, it is not the end. We learn from failures, as well as successes. What did you learn from this experience? Should you approach the obstacle differently? Should you change direction and avoid this obstacle completely? You can't avoid many obstacles in the military, but you can still maneuver and work with your teammates. Whatever the challenge you face, don't quit over one failure.
You are in charge of your life and your career. Some obstacles in life are unavoidable, but many can be out maneuvered. Network with your friends, coworkers, and mentors. Ask for their advice. You are not alone. Whatever the challenge, other people have faced it, as well. There is more than one way to solve every problem. Focus on moving forward.