Question for any doctors, GP's or endocrinologists please - 10 points?

I'm being tested at the moment for cushings disease - and as this is taking quite a length of time for results, my symptoms are getting worse...the ultimate bothering me is weight gain. I'm wondering does anyone know if its possible to go to my GP, ask for a prescribed dietary aid in the meantime, i feel stressed, anxious as it is but i feel like they already think im a hypocondriac, so i would like a professional answer first pls. thanks x