Hi Last Week I Started To Get Diarrhea, Nausea, Loss

Hi last week I started to get diarrhea, nausea, loss of hunger and just not feeling well in general. I went to the doctors office and we figured it may be food poisoning. 3 days went by and I didnt feel better and was loosing weight so the doctor gave me fluids, ciprofloxacin and zantac (for my upper stomach because it was hurting and I have had issues in the past with an ulcer forming). I also started to develop dizziness and i was concerned about parasites because I live in the caribbean and I went to a waterfall to swim a week before. I dont know the results of the fecal yet but it has been a week and I am still dizzy and now have small rashes that have developed on my stomach and back. Could the rash be from the food poisoning?