Jump Rope NOT

Well I tried the jump rope and I have a new found respect for people that CAN jump rope. They make it look so easy. I felt like an elephant when I jumped for 5 SECONDS, forget 5 minutes. Although I have started walking 3.5 miles, I am afraid that just won't be enough to keep me from dying at "camp". It's really not the physical activity that scares me it's the possibility of getting injured that has me worried. I am very limited in what I can do at this weight.............which will remain a secret to all except myself and my God!