I think I have pneumonia. Help?

Ive been sick for about two weeks now with a really bad sore throat and I’ve been pretty dizzy and weak. I went to the ER a few days ago and they just said its a simple sore throat and there is nothing to worry about.

Since last night I haven’t been able to sleep and I’ve been throwing up bloody mucus and vomiting whenever I cough. I’m also starting to get the shakes and a bit feverish along with my nose running like a river. I’m scared to go back to the ER because I don’t want to have to deal with them thinking I’m pretending to be sick. It also hurts when I breathe and it is hard to breathe.

I also have work today at 12:30 and I don’t know what I should do.

Please help.