Irritable Bowel Syndrom, Gastroesophageal Reflux, Major Depress

I'm a 21 year old female, and ever since I hit my preteen years, my symptoms have been:
1) Irregular Menstrual Cycle

2) Irritable Bowel Syndrom

3) Gastroesophageal Reflux

4) Major Depression

I want to know what problem in my body causes all of these symptoms, because I have seen doctors, therapists, councilors, and taking many anti-depressant medications that have yet to solve any of the following problems listed.

I'd like to figure out the root of the problems so that I can treat myself properly as my condition is worsening periodically.