I'm 21 and I've just started my first year in university, before that I was working for 2 years.. I've been on YouTube since 2013 so I've had a lot of experience on how to balance life and YouTube and it's a hell of a lot easier to do if when you're working tbh! (I didn't work a massive amount of hours a week which also helped)
Now I'm at Uni I'm finding it much harder to balance everything since I have to balance my actual Uni hours (which including travel time is 8:45am - 6pm), working at home, social life relaxing AND YouTube, which is more than when I was working which was just work hours, Relaxing and YouTube,
I honestly find the best way to balance everything is to set yourself goals, planning videos in advance, filming in bulk and setting aside hours in the week to commit to working on videos, almost like a job, and if you're feeling to stressed out you CAN take a break, nothing is really on the line!