HELP!! Can they take my license??

So... in October of 2008 I was an LVN working three jobs, really stressed, and going to school full time for my RN. I was trying to quit one of the jobs but I was guilted into staying. On a particularly bad day I had was at the nursing home. My pt was an 80 yr old woman complaning of shortness of breath. 02 sats 96% on room air, lung sounds clear. I called the doctor and he said to give her xanax and tell her not to worry, he'd be in later to see her. So I did. But the DON wanted me to send her to the ER but first give her a breathing treatment. the MD didn't want her sent to the hospital. So I charted the breathing treatment and I meant to go give it to her but I got side tracked. The DON asked me if I gave it. I said yes because I was nervous and I had already documented. She asked me again ten minutes later, and I told her yes. Finally the third time she asked I admitted that I had lied. And I was so stressed out I counted with the other nurse, told the DON I quit, I clocked out and left. Yesterday I got a call from an investigator with the state and he wants to talk to me about it. I am an RN now and I know what i did was wrong and I feel horrible. WHat should I do? can they take my license?