Camelot - obviously he lives with you, if your not paying for his college how is he paying for it? Loans? Himself? Does he have a job? Does he have his own car?
I am 22, I am in college - working towards my bachelors - I have a soon to be 6 yr old daughter - and at the moment I only hold a part time job but thats because of our economy in this small town - and everywhere needs experience that isn't a food joint or convenience store. Roxboro has lost 5 of the 7 factories and major job suppliers in this county in the past 7 years.
I take my college courses - I have all A's except one B that haunts me from this past semester.
I do job searches every other day - I put in calls to places every Monday to talk about possible interviews - I do almost all the house chores since I live my dad right now because when I lost my job I just didn't have the means to live where I was living.
My parents will do everything they can for me - but lazing about would put me on my butt. I have seen what its like living on my own - how hard it is - and I don't take for granted what I'm given and allowed to have at this point.
Honestly it just sounds like he needs a good kick in the pants seat and a wake up call.
He has to understand that he just CAN'T coast through life - he gets into the college he'll have to WORK at them classes and courses - and point out that he's A. paying for it or B. be paying for it later - especially if he has a grant - if he fails he'll owe that too. And if you fail classes or drop out with loans and grants - you usually have to start paying on them ASAP...
Remind him of the things you do for him - then point out what he doesn't do to contribute. Point out that yes he's 20 - but he's under your roof and he doesn't have to be - and if he wants to act like a child and procrastinate over everything - you'll treat him like one.
If the car he drives is yours : only allow him to drive it to school - and no where else. Take the keys away. That'll hurt.
Does he have a job? If not - tell him he needs one to help pay bills and stay in your house....mean it.
P.S. good luck! I don't know what your going through - I'm not there yet - lol. But I've seen my parents, cousins, aunts, etc raise kids and all and I'm at that age I understand what may or may not be going through his head.
Take care and have a good one! I hope he wakes up and gets energized about something! He has a passion about something - he just hasn't found it yet.