Seems at least 2 of us have the same opinion about your situation.
As for breaking up the relationship, you rightly point out that she has a crush on you and, no matter what you do, its going to end in heartache at some point. You have taken a sensible attitude and seem wise beyond your years!
Advice: This is going to be a tough one and there will be tears. Knowing this and the way you are feeling about it I would suggest a fairly serious heart to heart with her and be nice about it and explain that, at this stage in your life, you need to concentrate on your studies as next year you have some important exams to face. Your Mum and Dad have obviously been very supportive and you don't want to let them down and she classifies as a 'distraction'. It doesn't mean you don't like her or are not flattered by her attention and 'crush' (which incidentally is sweet, but might fade as her tastes change too) She may say that she still thinks you can go out together despite this and be very persuasive (girls do that!) but you need to harden your heart and be firm. Its something you just have to do.
As for the guitar lessons, good on you! Once you learn the basics and the structure of the instrument, make sure you practice scales and cadences and work on the chord structures. Who knows, we may end up playing in a band together at some point!
Good luck!
Knight
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