That should buff out.Here is my shin 24 hours after the accident, all cleaned up and much smaller. Hard to get a perspective, but it was smarting...
Coincidentally, I was almost in the same position as you a few weeks ago. I had a destination in mind that required climbing a steep-assed hill that started off with gravel but quickly became golf ball sized rocks. The rear lost traction so my forward momentum quickly died, then trying to hold my position with the front brake turned out to be impossible as I slid backwards about 30-40 feet with the front wheel locked the whole way. If there had been the least little bit of mud I would have done worse than you. Get well soon, glad you didn't lose the leg!!