You have tendency to brood over the past and you need to overcome it. Whatever happened with you in 10th is a past and you have paid the penalty in form of 12th result. Now you have to decide that how much more you want to pay for this. Regarding your friend, let him remain as a friend; keep in touch with him and that’s all! Why you should think beyond this when nothing further is possible? Once you clearly understand these two facts, things will start getting in to order. God bless you.