sneezing super hard unexpectedly and pain in my old c section scar

So today, I was working on paperwork and I suddenly had to sneeze. I lost a baby in October so I'm super cautious. Sounds funny but I always hold my old c sect scar when I pee, sneeze or do anything with pressure as I feel scared I'll abort again.. Well this time I didn't and I had this horrible pain there, at the same time I got dizzy and light headed and began to gag like I wanted to throw up ? Wierd huh, I'm tender there low on my lower abdomen and it gave me low back pain. Is this normal?