Here's the thing with getting a job. You really shouldn't give a rat's ass if it's a dead-end job. I've made some friends through job training on the job that I just got and I only started a week ago. While I'm trying to finish my engineering senior capstone report so I can get a career job with my degree. Just because you're working a low-end job doesn't mean that it isn't a good stepping stone. You're 21 and you have absolutely zero work experience. None. Zilch. Nada. Null...oh wait shit The point is, you'll use a low-end job now in order to move up the ladder, even if it's at a different job down the road, since at 1 course a semester you're not getting a degree anytime soon.
I guarantee you that going to 1 algebra class a week isn't generating relatively much homework and you don't write proportionally enough to take up the other time by your own admission. You really don't do much so it's difficult to get out of your own way half the time. And doing nothing will make you want to sleep more. And so on and so forth. Getting a job will *GASP* take up your precious free time, yes, but it will make you actually get up and do something and it will actually make you appreciate what free time you do have.
Before you say that the job market's tough, there are plenty of minimum-wage places looking for people with very little to no experience. The people with experience or degrees are going to bail on a job much faster when a better job comes up. Hell, get a job at a call center. They're always hiring and the one where I live will literally hire anybody. It's better than Mcdonald's pay-wise. If you start appreciating the free time you have once you actually get a job and don't have much time to yourself, I guarantee you that you'll want to use it up doing productive shit. It can be writing, working out, actually making friends, whatever you want.
...why did I just waste this much text I mean seriously it's going to go in one ear and out the other