I had a nasty fall about 6 weeks ago now which resulted in a different type of wound ... much deeper and not so wide.
I went to the local clinic and had a nurse dress it for about 4 weeks, initially keeping it as a wet wound using Inadine and clearing off what slough they could with each visit then as the skin grew under letting it become a dry wound using something else but I can't remember what it was called which helped to encourage the remaining slough away.
Really would see a medical professional and let the treat it for at least a couple of weeks and until it's in a better state than it seems at the moment.
if you want the pic of my would let me me know and I can whatsapp it to you or try and work out how to get t from there onto here.