I didn't make a typo btw, I want to play baseball, not basketball.
Prioritise a bit.
Allocate yourself certain times for writing (and then stick to them). Give yourself maybe a couple hours a week.
Do the same for drawing and the video-game.
I would suggest dropping the piano (mind your toes) if you're not overly bothered about it. It's a hobby that does take a LOT of time and practice.
If you don't drop it, then I would suggest dropping either basketball or skateboarding.
If you want to learn basketball, rather than in your free time, it might be better to just get some friends to play it with during breaks at school. That way you're using free-time that you have to have.
I guess I'll go with this answer here. I'm probably going to drop drawing and making music for the time being, and mainly work on writing and making video games, as those are what I'm probably going to get a job for. I'll most likely work on piano, baseball, and skateboarding during my free time.