The message was delivered and I'm not looking for bullshit justifications or half-assed apologies that won't matter a week from now when the attitude doesn't change at all because we give five thousand second chances thinking "He's working on improving let's keep him." A good friend here always says "Don't talk about it, be about it" and I think that's a lot better than "I'm sorry" or "I did x because y."
Show it or you're leaving.
Now, back on topic:
I was referring mostly to my habits in person, but what makes you say that?
The best personal advice I can give is not to sweat it and, with as little stressing as possible, work towards what you can. My 12th grade year was arguably the best year I had of school just because I got pressured into going to prom and grad bash and whatnot when I originally, and very adamantly, intended not to. I figured, hey, if my friends want me to go to the point that they get a form themselves, go around for all my teachers to sign it while I had no idea, and then had me just write my name on it, then sure, whatever, I'll do it. This was the same year I failed two classes because my (home)work ethic was terrible and I could not stand sitting around at home doing work while I was surrounded by distractions. I made them up online after school for like a week and nothing of value was lost. Obviously I'm not saying fail your classes and don't worry about it, but I WOULD say to see if you can't do anything online to make room for the classes you'd actually like, maybe? At least see if there are any ways to get around to the A-level art classes anyway, like Jacze said.