Hello dear, it is really difficult to overcome betrayal and break up in a relationship. Howsoever, you should remember that right now is the time to focus on your studies, coz if you don't do well in your exams presently, the hurt is going to be much more. For now, surround yourself with family & friends, don't stay alone, have a daily routine pinned up on your wall from 8 am -8pm which should include regular morning walk, some yoga, some pleasurable activities like reading, music, painting besides studying. Eat at regular intervals, take care of your sleep. Try to keep in control of your thoughts by using distraction and relaxation techniques. With time things will get better. Whether you want to get back or stay apart is a decision that only you can make but right now your focus should be clear. I hope this helps.