4 weeks pregnant and OMG!

OK, I just found out I was 4 weeks 2 days ago. As usual I have the sore breast and acid reflux. But now I'm having really bad nausea when I drink water. Is that normal? I'm also having diarrhea and bad gas. I feel bloated all the time. It really sucks laying in the bed one minutes then having to vomit the next. I go into sweats when that happens. Should I be feeling all of this so soon? I laugh at myself because these changes are random. Another thing, I also developed a cold and it has my throat really sore. What medicines can I take that won't harm the baby?