When I was in school and doing YouTube, I usually just filmed on Saturdays, and I always did my homework on Friday night so I wouldn't have to deal with it on the weekend. However I can see how big of a problem it is if you're scattered. Thinking of ideas, keeping track of everything, and then finally filming. I don't know man, but weekends are definitely your best bet for now. You might have to devote an entire day or even the entire weekend to making your video(s), but if you enjoy it, it should be worth it.
Cut back on everything you don't need to do and get whatever you do have to do, done.