How are you able to pass background check for school

My problem was the opposite: I applied for nursing school and completed the background check with no problems. I got a job as a tech in a hospital, and that background check came back clear as well. Previously, I had worked for Homeland Security, and that background check came back clear. Now, in May, 4 days before I graduated, I got a letter from the TX BON that I'm being sent to enforcement for checking "No" on their background check. They told me I'll have to wait 4-6 months. Meanwhile, I had accepted, in February, an internship which begins now, I'm still waiting, and I call the BON once or twice a week which seems to really make them angry. I have no idea what to do, and I am extremely uncomfortable waiting on someone else to decide my fate. My arrest was a misdemeanor from 2001, and I never had to appear in court, never had to plead at all, and I was told for years that the County I was arrested in had no record of my arrest. I even completed my own background check on myself last month and still cannot find anything. I might lose my dream job over this and it is completely unjust.