might have a concussion

I am really worried I have a concussion. I was in an argument and I got so upset that I hit myself in the head, really hard. This was about 30 minutes ago. I’m not too worried about the concussion, I’m worried that I’m going to vomit. I have a major fear of vomiting, it literally takes over my life. So i am just here, terrified that I’m going to throw up. I don’t really have any other symptoms but I am nauseas (May just be psychological though) so if anyone can reassure me somehow or tell me what to do, that would help a lot. Thank you :)