God already knows whether you're truly sorry or not. He knows whether you're sorry that you lied to your mum, OR if you're only sorry that you got caught in that lie. You need to repent your lie to God, if you haven't already, and tell him you'll try to do things right from now on. He knows you will make mistakes, but that's because your human, and we all make mistakes despite our best efforts. You not only lied, but you broke at least one of the Ten Commandments: honor thy mother and father.
You say it's been 3 months already.. I'd say that 3 months punishment is a little extreme, BUT what you did, and what happened to you as a result, was pretty extreme also. So if you were expecting a week or two for grounding or whatever, then that's already gone by. It is our fervent hope that you have learned a big lesson from all this. Which is, that doing what YOU want, despite being told NO by your parents, can and will have big consequences. Actions always have consequences. You need to stop being so rebellious and stubborn about what your parents are doing for you. Believe it or not, they ARE just trying to protect you now. And since your old "friends" willingly and knowingly slipped you a mickey (alcohol in the OJ), then obviously they are bad and dangerous influences, and all the more good riddance to them. Try to bear this period with patience and a different attitude, and you'll get through it much better..