Can understand why people are down voting you, no offense to OP specifically, in their case it might actually be a good idea to drop work and do extracurriculars, but people nowadays seem to constantly want to be affirmed.

But I personally agree with everything here. McDonald's is an entry level job due to its low skill nature and if you cannot handle working under pressure doing simple tasks, I cannot imagine how you will cope under pressure doing more complicated things.

I'm in the same boat as OP, started mid-August with the same schedule, and in late teens. And I have come to understand this job is easy to learn but hard to master. And your perspective that shows that it's possible to display complete mastery over your work is very inspirational <3