Not that it will help this season, but looking forward to next season, begin to gradually work up the poundage on your bow.
When I started a few years ago, I could barely draw 55#. Each week, I would try to shoot about 3 or 4 days for a 1/2 hour or so. About every other week I would increase the poundage by 1 or 2 pounds (very similar to weight lifting). By the end of the summer, I had built up the muscles enought to draw 70# effectively during target practice. For hunting, I dropped back to 65# to ensure that after sitting in the stand for a few hours, and being cold, I was still able to draw the bow.

One thing you should also practice.....I found out this little tid bit the hard way.
Try to draw your bow, by holding your release hand in one place and pushing your bow arm out (kind of a reverse draw). Last year I had a doe come in at a funky angle where I couldn' t draw with my bow arm extended. I found that I couldn' t draw my bow more than 1/2 way (peak weight on the cams). Had to let her walk.