As someone with chronic leg and foot pain who can get shin splints from time to time, I highly recommend looking into getting proper insoles for your shoes. Treadmills have a bit of give whereas hard pavement does not, so it's a matter of getting your muscles adjusted. Power through and your legs will build up a tolerance to the shock level eventually.
You may want to try running on a soft dirt path every now and then to give your legs a break.
I use a fit bit to track myself! Great investment.