Scared of Headers

I’m a 6’3” centerback, and I’m terrified of taking headers. It’s not the fear of pain or anything, I just shy away by reflex. I just started playing for the first time this summer and I’m already on the way to being on my high school’s varsity team, but this issue is the biggest reason I’m not there yet. My coach absolutely hates it and doesn’t understand why I’m not winning every 50/50. I also feel that way. I just need some help with the mental aspect and how to fix it. Thank you 🙏