I Have Been Injecting Humulin R U 500 Insulin For

I have been injecting Humulin R U 500 insulin for the past 6 months. Shortly after starting the insulin I developed severe cramping in my hamstrings and calves. It's been painful to walk. Could the insulin be causing this? I am on large doses of insulin (165 U in am- 175 U in pm ). My endocrinologist says no.