Are these symptoms of getting sick normal after having diarrhea? Am I contagious?

Okay this is gonna be a little tmi but I had diharrea for the past couple of days it was really bad, I called out of work and I took some otc medicine and now my diharrea is gone, but now I am starting to feel sick? Like I feel that I have a big headache and my nose is very congested, and I feel "mucus dripping" down the back of my throat if that makes sense, am I okay to go to work tomorrow? I called out on Tuesday. What can I take to make this mucus feeling go away?
Are these symptoms of getting sick normal after having diarrhea? Am I contagious?
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