I'm on my third week of university. I have a story coming out in an anthology in December. I have no time for anything other than those two things and even those I'm having difficulty making time for. Want to do well in school? Oh, well then you can't write. Want to write? Well then you probably shouldn't go to school.
People have been trying to tell me this for ages. They've been trying to tell me school comes first. I do know this, of course. I am a mature, responsible adult and I'm paying a lot of money to be in this school and learn these things. So why wouldn't I put school first? But that's not the only question I have. My other one is: why can't I make a half hour a day to do a little bit of writing. Beyond the fact that it gives me a break from the never-ending essays, readings, and lectures, I need that half hour to myself. I need just a half hour to myself to keep me sane when all I have time for at all other hours of the day is schoolwork. Read this. Watch that. Listen to this. Write this. But never, take a few minutes to yourself.
So this is my opinion. Whether it's writing, or some other hobby or talent, make a half hour a day for it. A half hour is going to make the difference between you passing and failing. Not because it will affect your grades. It will make the difference because when you make that small amount of time for yourself, it will allow you to keep your mind more focused when you turn to schoolwork.
Believe me, it works.