Your 52 lb is every bit up to the task of taking deer. Yes, 68" is kinda long in a treestand, but it's not near the issue that we think it will be, especially if you plan around it and practice some. However, if you have some doubts about the bow and it messes with your confidence and concentration, then it would do you well to change. Definately figure 60 lb to be your max at least for now; 55+ would be plenty. There is a bunch of difference between 52 and 60 on a chilly morning. Ordering a new bow probably won't work as it takes a while to have a bow made unless you find something already on the bowyer's rack. Shop the classifieds and you should be able to find something to your liking pretty quick and well within your budget. I have a couple of 64 inchers that would probably work for you, but that is only 2 inches less per tip.
Practice, be patient and enjoy the journey. Keep in touch with us.