What Causes Weight Loss Along With Constipation And Stones In Kidney?

Hi I was diagnosed with hpylori 3 years ago. Before hpylori i weghed 125 lbs my idea weight, had lots of energy and very active. I then has a serious fall and had a few bulging disc in my neck and back. Went to see pzin management dr., neurologist, neck and spine specialist. Had epideral and steroid injections, noproxin, and gabapentin for pain. Developed severe constipation. Got better but continue the severe constipation. Went to my doctor gave me nexium. Went again referred me to gastroenterologist. Said i hzd hpylori gave me triple treatment 3 times. Had colonoscopy and upper GI. Had gastritis and diverticulosis. Said both were mild. Gave me delcolax said to eat special k every morning and lots of fiber. Also gave me polygleco not sure how to spell it its a laxative. Anyway I now weigh 110 lbs, have severe constipation, cant eat almost nothing without getting constipation. Saw another gastro dr. Last week said i had IBS and prescribed linzess. What is going on with me. I also have vitamin d deficiency. My dr. Fave me 50,000mg of d for 4 weeks. Developed kidney stone. Very painful. Im constantly being rediagnosed. And treated. All i want is to gain some weigh, stop the constipation. Stop using laxative and go on with my life. I have never drank alcohol in my life. I have never use or tried illegal drugs. There is no history in my family of this. How can i improve my quality of life. I do drink coffee and water in the morning. Never nauseated. Please help by telling me what kind of dr. To see and what i need to do so they listen and stop this vicious cycle they have me on. I have spend thousands of dollar. I even have dental cleaning as schedule. Thank you in advance.