Its all in my head????

So I've been having trouble with my leg where it feels like dead weight and I can't put a lot of pressure on it without it feeling like its going to give out on me again. So I went to the doctor today and you know what he basically said to me???? He said how my brain told my leg to shutdown and by not walking on it I just made it worse. Now you tell me...how am I suppose to walk on a bum leg? Meanwhile hes doing these exercises on my leg and making me walk and I'm cringing in pain. So now I have to go get an MRI to make sure nothing is wrong with the muscle. What is it with doctors and nurses? They don't let you use crutches when you need them without a doctors note and then the doctor complains about them not letting you but says the pain is all in your head. I mean really, has society really become so paranoid that they won't even believe if you're in pain anymore? Is our society really based on just making more money or being jerks?