If you aren't feeling well, you might want to let a doctor check it out for peace of mind. Especially, if you blacked out after hitting your head. Things to look for after a head injury are vomiting, pupils not reacting to light appropriately, anything that seems out of normal neurologically. I would avoid aspirin and NSAID medications (can thin blood or make bleeding worse) until you see a doctor. Best wishes...
It is a good sign that it is improving but it would probably be best to have a doctor check it out. This has some information that you could discuss with a doctor:
http://www.mayoclinic.org/diseases-conditions/concussion/basics/symptoms/con-20019272