Jessie James Decker is fighting a mysterious illness.The 37-year-old country singer opened up about her health in a series of Instagram stories, sharing she hasn't been feeling well the past few days.In a story posted last night, Jessie can be seen sitting in a hot tub, with the words, adding the caption: "Feeling a little better today…still a slight fever and tummy aches, but after the day I had yesterday, I’ll take it." Decker added that she is "trying to sweat this thing out now," and that whatever she has, "has kicked my butt." She also included a question box, asking
