Your story is almost exactly the same as mine. My leg and hip muscles got progressively weaker until I was only able to walk for about a minute before intolerable pain would start. I thought it was from a ruptured disk from over 20 years ago. My walk eventually became a waddle with little, short, mincing steps. Since diagnosis and starting Mestinon these symptoms are much improved. Now I can walk about 10 minutes before I have to sit down for a few. Then I'm ready to go another 10 minutes. I recently bought a Rollator so that I no longer have to worry if there is a chair or bench handy when my muscles give out.