Driving test

So I am 23 I have my drivers test this Wednesday.. I have PTSD when it comes to driving because when I was young I almost got hit by a car but my big sister pulled my shirt. Then when I was pregnant with my 1st child in 2015 I almost got into car accident by my moms ex on purpose since I was with her in the car. He slammed his breaks and my mom slammed Hers. Well 5 month ago when I came out the hospital giving birth to my second child when my ex bf was driving he wasn’t looking while pulling out of a drive through that we almost got into a big accident.. I am nervous asf and I keep thinking ima crash. How do I calm down? It’s so bad that when I think about it I have to go to the bathroom because I start feeling sick. Any advice on how to look past the nervousness?