I think doctors in general often have a callous attitude toward people who are overweight. They consider fat people to be deliberately causing their own health problems and I think for that reason the doctors see the fat people as lost causes or people who need to be reprimanded.
I've looked around on some pro-fat sites. I don't agree with their main philosophy, that being fat is acceptable or that being fat is healthy, etc. but I did find some good information there which I'll share.
They say that if you have a health problem, and you're fat, that doctors will automatically attribute it to your being fat and won't be as willing to treat the problem.
For example, if you're fat and you have acid reflux, the doctors may just tell you to lose weight and it will make it better. It probably WILL make it better, but thin people also have acid reflux issues, and you should demand the same treatment that they would get for the same issue.
I think you need a different doctor immediately, one who will treat you as a human being and not just someone who needs to be scolded.