What Causes Sharp Pain In The Lower Abdomen?

Hi.... Friday morning at 4 a.m., I was woken up from a sharp pain in the middle of my lower abdomen. I went to the bathroom and just urinated. When I got up, I felt this strange sensation in my head like I was going to pass out. I tried to get back to my bed and as I entered my room, I felt myself fall backwards, I screamed and hit the back of my head on my door. The next thing I remember is my husband yelling my name. When I came to. I realized I was on the floor. I immediately started sweating profusely and then started to vomit non stop for at least 30 minutes. I was drenched from head to toe from swear and there were huge droplets of sweat on my arms. My night gown was completely soaked from sweat. When I finally stopped vomiting, I crawled to my bed and my husband had to help me get into it. I fell asleep but kept waking up as if I was coming out of the passing out episode again. This happened two or 3 times until I finally woke up and was aware of my surroundings. Since then (3 days ago) I ve had this burning pressure sensation in the entire left side of my brain. From the front to back and even in my ears. I didn t go to the hospital because I ve had this sensation several times before but not from passing out, but only have passed out 3 times in my life. I take medication for BP, diabetes, fibromyalgia and neuropathy. Did you know what could be the cause according to symptoms I had/ Have?