Suggest Treatment For Itching All Over The Body With Tiny Blister

I have been itchy all over for about two weeks. It started on my head now all over my body. When I scratch the top of my hands it swells a little like a bug bite then becomes a tiny blister. When it pops clear liquid comes out and it becomes painful scabs and no longer itches. I also have had insomnia for about two days PLEASE HELP.