Diarrhea is typically caused by some pathogenic organism, could be bacterial or protozoa parasite - seldom do worm parasites cause this.
You need to go to the doctor so they can do some stool testing on you. I would attempt to treat this yourself. A lot of the info on parasites is errant anyhow and in many cases people are just wasting time. I would see a doctor and if that is no help then come back here and repost or send me a pm and I will tell you what to do.