Male; 22; ~200 lbs; duration of sickness 2 days

So for the past two days I had severe sneezing and stuffy nose probably relating to weather changes. I took Zyrtec on day 1 but I didnt really see any improvement and just noticed my stuffy nose getting worse (relying on breathing through my mouth). So I thought I should give Mucinex for nasal/allergies a shot, but my dumbass accidentally took a Walmart version of Mucinex for Severe COUGHING and congestion. I have NO issues with coughing and respiratory congestion (unless breathing through mouth is considered congestion), so now I'm concern 1. I might experience adverse effects because I took a medication I dont need and 2. my real symptoms are not relieved.

The medication i accidentally took has: Dextromethorphan , Guaigenesin, and phenylephrine HCl. It's advertise as maximum strength.

Would this medication actually help my stuffy nose and sneezing? Or should I take something else? And what medication would be safe to take when I just took that walmart version of Mucinex?

Thank you!