I (17F) rolled back in traffic and hit the car behind me, having so much anxiety.

I got my first car on Tuesday (I'm still only a learner) and today me and mum drove it to the local supermarket. Only, because it's different to the car I've been learning in, it took a lot of getting used to, especially clutch control. When I was 11 my dad died in a car crash, and the result of that is that I have GAD and PTSD. I have always been an anxious driver, and the thought of a car accident makes me instantly want to throw up and digs up so much anxiety. Nobody was hurt at all and neither cars were damaged, but I can't stop the feeling that I'm a terrible driver and I endangered the lives of other people. I also feel as though I've let my dad down a lot, and nothing I'm doing is helping these feelings go. My confidence driving that I've spent 7 months building up has now been completely knocked again. Does anybody have any advice/been through a similar situation?