amount of cocaine over that amount of time

I have been living on my own since I was 16 after my mother passed away, and have lived a relatively productive life, though I did begin smoking pot and drinking soon after I was kicked to the curb. I graduated high school, joined the Air Force - got kicked out for underage drinking and simply an inability to adjust to military life. I’ve spent the last couple of years in a drunken stupor. I have found the love of my life and desperately want to begin school March 31st to become an EMT, I currently work as a server, waiter. This requires a back ground check, a DUI only on my record, and a intense drug test. While on a trip two days ago to Cancun, I did a considerable amount of cocaine over the course of a week. I really don’t want to let this ruin my chances of entering this program, and have been trying to work out financial aid and saving money for a year, I am really freaking out. Does anyone know if that amount of cocaine over that amount of time could pose a serious threat, or would a intense three weeks of working out and detoxing be enough? DOES ANYONE KNOW!?!?!