What Causes Nausea,vomiting And Feeling Of Something Stuck In Throat?

I have been having muscle spasms and twitching and I m tired all the time even if I get 7 hours of sleep.....also just yesterday I ate pizza and I started feeling nauseous and felt something stuck in my throat ...i haven t stopped vomiting and the feeling in my throat hasn t gone away;I also get this weird feeling all over my skin . I don t know if it is all related but I m getting worried_francis ruiz