I've been calling my doc for 2 days now. I guess bc of good Friday they're a little backed up bc…

I've been calling my doc for 2 days now. I guess bc of good Friday they're a little backed up bc I've yet to have my phone called returned. I need to know if I can take Robitussin CF night time max. I've been so sick for the last 4 days and Benedryl isn't helping. I cannot stop coughing which is interfering with my sleep and making my ribs and throat hurt pretty severely. Can anyone answer this for me?