1. My mistake for failing to recognize that you want to go to business school (which is clearly indicated by your saying you want to take the GMAT).
2. Why didn't you take the GMAT as expected?
3. You need to address your drug problem.
4. The military is always an option, replete as it is with post-9/11 incentives, benefits, and bonuses up the wazoo; further, a 3-year active duty commitment unlocks GI Bill benefits, which are substantial. This would add a powerful element to your resume, a source of funding for school, and probably excise the apparent laziness and drug problem from yourr current personal disposition.
Since GMAT scores are valid for five years, you could study for it then enlist, subsequently applying with your still-valid score after your active duty period (though you'll be gambling in the hopes that the country doesn't get into another war for half a decade, which might require your activation from IRR -- a task this war-obsessed nation may well fail to achieve).
Edit: They've also just instituted a Roth TSP, a great retirement vehicle for someone so young.