I'm doing the same thing, though probably 7 weeks ahead. For me, diet AND exercise are key. And not just weights, but aerobic, also. I read recently that getting your heart rate up for 150 minutes or more per week is good for both fat loss and heart health.
I live in NYC as well, but luckily my building has a gym (tho small, I can do all I need) so I have no excuse not to get back in shape, lol.