What could result in sudden excruciating lower abdomen pain?

Hi doctor,

My problems began three days ago. Suddenly I felt dizzy, had trouble keeping my balance, and everything turned yellow. I tried sitting down for a bit and standing up several times. My friend got concerned once he realized I was not overreacting. I suddenly felt the need to go to the bathroom and sat down again. I do not remember what happened, but I woke up to my friend slapping me and saying I had fainted. I insisted I did not need to go to the hospital. However, the next day we were walking around town when I started feeling what I thought was my period cramps coming on. I asked my friend to wait by the restroom while I went in to put in a tampon. I had not made it into the stall when what I can only describe as an excruciating pain shocked my lower abdomen, sending me reeling to the floor of the empty bathroom and the force of hitting the floor causing another ripple of pain.

My periods are always relatively mild, and even when the occasional cramp hit, it was not nearly as debilitating as this was. After around five minutes of gasping in pain on the bathroom floor, I was able to get up alright and hurriedly shoved a wad of toilet paper in between my labia, concerned that I was giving a mini birth to a huge chunk of my uterus. I felt fine until we were in the convenience store searching for pain relievers when I felt the second wave coming. Doubled over the entire way groaning in pain, my friend paid for the medicine and ran out the door with me. As soon as we sat down on a park bench, I promptly started salivating and vomited for a few minutes. Afterward, I took the medication Menstridol for the cramp and tried to poop, and I felt a little better. I am usually very tolerant of pain, and this whole thing has been terrifying. Could it possibly just be my period? I have never had cramps or symptoms like this before, and the whole thing with the fainting was just weird.