My Hair is Ruined

Since my hair has been growing rapidly since I dyed it awhile ago, I decided to get rid of the roots and go back to my natural color today. I knew it wouldn't be easy, but I figured I could get it close enough that it wouldn't really matter. I knew that I would have to lighten my hair color first since my natural color is lighter then the black I did.
I lightened it, and it worked pretty well. My roots were a different color then the tips, but I didn't think it would matter much once I darkened it. I did my second round of dye. Things didn't go as well as expected the second time around.
First of all, my scalp started burning. I don't mean it got a little warm, but it felt like it was on fire. I know that can be a sign of an allergic reaction, but I didn't care. I just left the color in. I couldn't get the water cold enough when I rinsed it out. Washing the dye out felt like someone was rubbing sandpaper across my head.
I dried my hair and looked at it. My hair looks like a dyeing campfire; embers under charcoal. Somehow, my roots turned bright orange, and my tips are still dark. I can't put anymore dye in my hair. I'm scared my skin will fall off. I'm just going to leave it like it is. I don't care anymore.