I need help with an Military Reenlistment Question?

I enlisted in the Navy Reserves out of Bellevue, NE when I was 17 in 2006. I was living on my own at the time and barely graduated high school. I enlisted because I wanted to get away from the crowd that I was hanging around. So I went to boot camp and to A school. I checked into my Reserve Unit and every thing was okay for about 4 or 5 months. I started hanging out with the wrong crowd again so I asked some recruiters if I can transfer to Active Duty Navy or go to Active Duty Army and they said no due to my contract. So I fell back into old habits and told my Senior Cheif that I wanted out and he told me to stop showing up for my drills so I did. Eventually I was discharged with an RE Code 4. I realize that I was weak and immature. I am now 23 and would like to enlist in the Army. Ive talked to a recruiter in Stockton, CA, where I live now, and he mentioned that I might be able to get a waiver for the Guard. But since then he hasnt returned me emails. Is it possible to enlist in the Army?