21 yr old male with chronic stomach upset and chest pain

I am a 21 year old male who for the last six months has had stomach pain, gas and bloating, loose stools with excess mucus, alternating constipation/diarrhea as well as chest pains located between my ribs. Over thanksgiving break last year I ingested hallucinogenic mushrooms (stupid I know) and ever since that night my stomach issues have not gone away, they just alternate from bad to worse. I am normally a healthy individual eating healthy and exercising regularly, however these stomach issues have really taken their toll on me. I frequently wake up in the early morning with stomach discomfort and no matter what diet I eat the pain is always there. I am unable to do normal things and things like exercise and going out to dinner are near impossible. Medications like antispasmodics and probiotics have also had no effect. I have been to a gastroenterologist several times and received an upper endoscopy, colonoscopy and CAT scan of my digestive system and accessory organs; all came back normal. The doctor really didn't have much to say and said that it is most likely an functional illness like IBS. However, I find it peculiar that it all started immediately after the mushroom ingestion.

I was just wondering if anyone had any suggestions on what I could try to lessen or rid these symptoms. This problem is really starting to impact my mental health, because there is not a single day where I feel normal or healthy, and my stomach is constantly a burden.

Thanks again,
aeyjekn