Blanconino,
I'd take AWWCRAP's advice. Don't take more on than you can chew. Your grades are important measures of getting into a 4 year program. Crap grades will hurt your chances of getting into a better school you ambition for.
Even though you THINK you may be able to handle more units, you could get yourself deeper into the rabbit hole. Then you're more fvcked. Is it worth it then? Your pride/ego will really take a beating then, especially when college counselors see these issues on a daily basis from all walks of life.
Your defiance can lead you to messing yourself up big time.
If that happens (i.e royally messing up a transcript), then I'd recommend to start over at another school and rebuild up a respectable transcipt. More time and money....YES....but your fault for not heeding to sound advice and letting your ego and impatience get the better of you.
Another option for you is to take loans, scale down the work hours and kick ass in school.....