Everything is not over. You should be thankful to GOD that you know the actual nature of that looser. As per my experience he is the person who always want to have any girl in their life. If he got someone then left you.
I am surprised that why are you so much worried for this. These are the experience of our life. Sometime sweet, sometime sour. If you have sour experience it does not mean that you life is finished. See the eyes of your parents who are dreaming of your bright future. If you loose your heart like that then you are not justifying your responsibilities for your parents.
I suggest you to leave that boy immediately for ever. Delete him from your life. Remove him from all your contact, remove him from all your friend list.
I am sure that you will get a good partner in future. Believe me as time passes your wound will heal and you will feel better.
So tight your horses for your exam, and build your bright future. People like him don’t deserve a nice person like you. Kick him out.