Things burn and crawl for me too, esp. the burning.
I think that the burning seems to happen when I touch some dry texture like cloth, paper, etc. that bothers me. It thnk that the crawling sensation happens when something brushes up against me like certain loose styles of clothing, someone rubbing my back,
One thing though, is that breeze or wind against my skin burns instead of "crawls."
I do occasionally get nauseous and a headache and such when I get overloaded from sensory imput. The feeling sometimes accompanies a shutdown as well, but not always. And now that I think about it, I do sometimes feel sick like that when I have to touch something that the texture of it grosses me out, although the feeling isn't really either a burning or crawling sensation.