What would YOU do in a situation like this?

I took a midterm exam last month. There are over 60 multiple choice questions worth 1 point and there were like a couple open ended questions on the back worth at least 2 points or more. I used my iphone to get at least 7 of the answers right and I copied at least 25% or more of the MC answers from the student next to me. He seemed cool with it. The teacher was not aware of me cheating because she would have taken my test away. 2 weeks later she tells us our grades and my grade a 4! Yes a 4/100! How's this possible? Even if I didn't cheat that still would be impossible. A 4 out of over 60 right? I know for a fact that 4 wasn't my grade. I was expecting to fail but not that bad! I'm willing to admit that I cheated if I figure out how I got a 4. And btw I know I got at one open ended right since I googled for the answer! I know that cheating is bad and all but WHY TF DO I HAVE A 4?! What would you do?

I'm not sure that grades are the same as marks, you should check.
But as to cheating (an anagram of teaching!) I don't think your teacher is as green as you think, most of us can tell when a student has cheated so she probably gave you the marks she thinks you deserved.
In education the only person you cheat is yourself.

Your teacher saw you using your phone. Of course you failed. A test shows whether you learned the material in the class. You clearly didn't.