Military schooling help?

I talked to my local recruiter and he said I needed 15 college credits. I have a Penn Foster Diploma High School. I am 17 and dropped out of college what can I do. I want to join the Army but it seems the only way I can is through college. I asked them if I could go back to my local High School and they said yes is this true. Also I told him I had asthma after 13, and I took my self off my medication at 14 or 15 and I didnt have any problems. He told me as long as I get cleared from the doctor I would be fine. I do still weezy when I run but no attacks plus Im overweight which doesnt help the carido aspect.