Throbbing Pain In My Lower Left BackSide Not near My Spine?

I have a small cyst on my left Kidney, nothing big I dont believe, but I just last week had surgery on my fallopian tubes due to an ectopic pregnancy...Then 3 days later I came down with a UTI...Now for the past few days i have been in and out of fevers with pain on my lower left side (back) and I have been having diarhea for about 5 days now...What should I do...could it just be muscle pain?