Do I have stomach problems?

I went to my doctor about a year or so ago for Heartburn, diarrhea, unexplained weight gain, and no menstrual cycle. He took some blood and took a stool sample and the results came back normal. He gave me some medication and sent me on my way. Well now about a year and a half later nothing has changed, the diarrhea has become chronic (past two months very dark almost black), the heartburn is everyday no matter what I eat what I drink or how much pepto, tums, or prilosec I take it is sometimes unbearable I find my self purging to get rid of the pain, and I have a menstrual cycle about 2 times a year. Would these be symptoms of an ulcer? Can some one please help me???