What Causes Frequent Urination, Loss Of Appetite And Diarrhea?

Hi Dr. Rynne. I m a 58-year-old woman, white. For the past few days I ve been urinating more frequently, with a very small bit of pain (nothing like the UTIs I used to get when I was young). The past 2 days, I ve had nausea, loss of appetite (can barely eat), constipation (yesterday) and diarrhea (today). I have a bit of back pain around where I m guessing the kidneys are, not severe. I m very very fatigued. I ve been working a lot and have been under some stress. I don t know how much this will cost or how this works, so forgive me if I can t afford you and have to turn this service down. I have Blue Cross / Blue Shield. Thank you!