I Have Had A Sharp Pain In My Lower Stomach

I have had a sharp pain in my lower stomach that has left me nausea and dizzy I had it about 2 weeks ago and now I have just suddenly come down with it again , two weeks ago I had a headache that lasted about three days with it and my blood pressure was up and it has always been on the low side this morning I had diarrhea only twice though the pain feels like if I could use the bathroom it would feel better, thought it might be gas but Iam so week and dizzy.