Shelly, I have been experiencing the same thing for a couple of years now. Diarrhea every day, sometimes up to 30x/day. I had a ton of weight loss, fevers, and abdominal pain as well. There was some evidence of infection, but no one had any idea what it was. Sometimes, as much as we wish and hope that medical science has an answer for everything, there is no great explanation for what ails us. And docs need to be humble enough to admit that. After a while, you realize that your only option is to learn to deal with it the best way you can. You have to, out of necessity. And you will! It will come slowly.
The people on this board have tons of advice, some of which will help you, some of which will have no benefit. It took me months to go through trying all the treatments - different diets, fiber supplements, fish oil, calcium, antibiotics, probiotics, anti-diarrheals, anti-spasmodics, narcotics, you name it - and some had some effect and others had no effect. Recently I was on a course of anti-parasitic drugs that seemed to help more than anything else has. It's likely that my problem is, in fact, a parasite since I have traveled to many extremely rural areas in Africa and South America for extended periods of time, but parasites are a beast to find and sometimes they just never go away like they should.
Anyway...my advice is to be patient with your illness, to really take time to try different things (calcium has worked wonders for some people on this board, as well as dietary changes; some people take Imodium or Lomotil for years, or they try Lotronex - has your doc talked to you about that one?), and to try to embrace the other aspects of your life, outside of the illness, that occupy your time and energy. You also might want to consider some therapy to address your anxiety, or even an anti-anxiety medication, so that you are not all-consumed with this.