Piano -

So, I'm going to college for music. Music therapy, to be specific. I have an audition for OU in two weeks (which is terrifying,) and I'm struggling to memorize the three songs that I have to play for the judges.
About an hour and a half ago, I was in my piano lesson for the week, and I did NOT have a good lesson. I practice like two hours per day! Not even joking! I get so frustrated when I mess up during a piano lesson. Should I really be going into the music field if I can't play right? It makes me so angry. Like the kind of angry where you're so upset and disappointed that it makes you want to cry. Why study music vigorously when, apparently, I suck at it? I've been taking piano lessons since I was four years old. That's THIRTEEN YEARS! I should be so much better by now! Music is what I've done my entire life! It's probably the thing I am best at, and I can't even do THAT right. I love music and it is my "passion". It sounds cheesy when people say that (hence quotation marks around the word) but it really is. When people ask me to describe myself, the first thing that comes to mind is, I'm a pianist. I love music and I do want to study it. But why bother when am I so horrible at it? =/ I think any instrumentalist can relate to this, really, because everyone has off-days with their instrument. But it's such a horrible feeling. I hate it!