Good for you keep it up! I tend to commute on Mondays only since I am the early guy, and I ride over the Brooklyn Bridge, to the Westside bike path to W57 st, its about 9.4 mile and takes me around 40 to 47 mins, depends on how hard I push it. When i first starting commuting, I had to rest 2 times. Once on the BB, it really use to beat me down, when going up and around Chelsea piers, now I can do it nonstop.

I am really thinking about using the Manhattan Bridge for my commute home. it is more bike friendly, meaning there are no tourist bocking up the way.

Your time will get better once you get in shape.