Worst period pain ever!!!

I've been having these EXCRUCIATING pains in my lower abdomen/stomach area ever since my period started yesterday. Every time I stand up, I get dizzy, lightheaded, and feel like I'm going to pass out right there. I feel super hot but I checked and I don't have a fever. It even hurts when I walk, sit down, lay on my bed, or just sit there and do nothing. I don't know what's going on. My periods are NOT normally like this!!! Also I have a dress fitting today and I can BARELY WALK. I can't cancel the appointment so can anyone Help???!!