My gf had to pee last night and then after she started gaging and sweating and feeling dizzy after she had a slight bladder pain she has been sick for about 3 days with sore throat and coughing

This . This sounds like a vasovagal episode. The vagus nerve controls and senses internal sensations. It acts to slow the heart rate but also acts to allow the bladder to contract. She may have already been dehydrated from her illness and then, when she voided, developed low blood pressure. Her sympathetic nervous system sensed the drop in blood pressure and then the adrenaline caused the sweating. The nausea may be from the illness or hypotension or both. I hope she is getting better, if not she should be seen with these symptoms and 3 days of worsening illness.