I just took mucinex dm 1 hour ago & I am coughing like crazy & want to get some sleep can I take nyquil now or

I wouldn't take it too close together. Mucinex probably aggravated your coughing since it is designed to break up chest congestion. Wait a bit and take the NyQuil. A better suggestion is to take the mucinex during the day and NyQuil at night so you can get your much needed rest.