I Am An Asthmatic, On Prednisone, Xolair, Ivig For Immune

I am an asthmatic, on prednisone, xolair, ivig for immune deficiency(as result of these meds?) and I am trying to find a way out of the vicious circle the "cure" puts my health in. I also have hypertention (HCTZ and atenolol) and GERD (Nexium). I am 70, female, and reasonably healthy otherwise. but I have constant diarrhea that my doctors don't feel is a big problem. but believe me it is. I feel like I am not getting all of my nutrition because of it. I feel I would like to seek help from a nutritionist, but how do I find one. I don't want an herbalist, or a "wellness doc". I've been researching "fasting" but feel I should do with pro help. my docs don't offer guidance and say stick with my meds. I am not excited about all the "warnings" of this path and I will try for a healthier way out.