Have not been able to function all day after a stranger yelled at me

I was yelled at today by a stranger in a mall car park after a relative stopped to say hello to me and unfortunately blocked someone from pulling out of their parking spot. Rightly the person was mad and my relative drove off, however the person screamed at me and called me all sorts of names. I tried to apologize and when that didn't work I told them to shut up and got into my car. I didn't start crying until I was driving off but all day I have not been able to function I am just lying around my house feeling sad and scared. I don't want to cook or eat or move even. Forced myself to get a shower which was so hard to do. I just feel like I have completely shut down. I watched a show that I enjoy which has made me feel alittle better but I just feel so upset inside. Has anyone ever felt this after being yelled at by someone? Is this just really bad RSD?