My stomach is on the fritz!!! help!!!!!! be serious too!?

ok so im 15 and pretty healthy- i excersise and eat right alla that- so for the past 2 years i had issues w/ my stomach it keeps me up at night and its very nausiating though i never throw up. ive been to three diff doc. all of which have preformed many testes and cant find whats wrong with me. i feel like ill be another episode of mystery diagnosis.! but so latly(ok this is really embaressing so be serious :/) my stool has this diarrhea look w/ filmy stuff and its not diarrhea for sure. but my stomach hurts and its like a billion degrees here and ive tried taking tumms, rubbing this spearment oil this chinese lady gave me-taking this wierd medicine from el salvador!!!! idk wat to do anymore. my mom gave me this flax seed drink stuff thats supposed tp work as a laxitive but its not doing much. idk ive also tried jst to get to sleep by lieing on my stomach, lifing my feet above my head on a pillow, have the room dark, rub it, drink water, warm milk (some nights but its hurts more so i stopd) thought i was lactoseintolerant but it still hurt aftr switching to almond milk and no dairy! watdo i dooooooooooooooo? basically any other quick tips for short term like being able to go to sleep and long term tomorrow or future routine wise???? help!!!!!!!!!!! thank you soo much :)