extreme pain

I'm in so much pain and I really don't know what to do.. I'm only 18 , and my mum never has any good advice.   I'm in so much pain with my stomach I mean I'm crippled in a ball, it's not period pain either. I'm vomiting and have diarreah, and the worst thing is I have eggy burps which make me throw up. That's what it stared off with, eggy burps , stomach pain then vomiting and diarreah. It's been going on for three days now and I'm in so much pain and I can't sleep I have rang my doctor but don't have an appointment until later , please someone help I'm really in pain 😔