That is impressive Power Player. When I first got back into tennis 6 years ago after Roddick won the US Open, I was probably a 4.0+. It took me 6 months or so to get my tennis fitness back. At that point, I was also strong enough to switch back to my 1 handed topspin backhand. Before that, I used my crappy 2 hander which I used my first 2 years of high school.
After 9 months, I was probably a 4.5+. I stayed that way until I started playing up at OTC. I lost against almost everybody there more than I won for the first year or so. It was also tough getting used to playing on clay. After that, the tide turned in my favor against most of those guys. Now with lack of playing time and injuries, I'm middle of the pack again.