I have been diagnosed with IBS but I am not convinced everything I eat is bloating me up severley

Everything I eat seems to bloat me up to the point where my stomache is rock hard, the stools sem to be getting stuck in my lower intestine, when I go to the toilet which infrequent my bowel never fully empties, I have been on a gluten free whet free diet for the past 3weeks, it does help as long as i'm completely strict about it, I was diagnosed with IBS but i'm not so sure, how can eating ruin your life because right now I have no life, I cannot eat in restaurants, I have to look at all the ingredients on the labels when i'm shopping for food, when I blow up i,m in excruciating pain to the point where I cannot even walk, I do not know what is going on with my body, I have been tested for coelic desease and thyroid and the tests have come back negative, I have also had a colonoscopy and that too was negative, I will be going back to my gp on fri for him to refer me to a gastroentorologist, I'm in despair. HELP