HELP! Anyone have this happen?

I was told by my surgeon that a 6 month pcp supervised diet was required. However, I have been having problems with my stomach and constipation when I eat well and take my vitamins. This started back in November and now my pcp says she will try to think of something to convince the insurance company to approve. My health is deteriating and I need this surgery so I will not be in a wheelchair or dead. Has anyone been approved this way? I have plenty of other health problems too.