Should i take benadryl tonight after taking first two doses of zpac or should i take advil cold and sinus?

Benadryl and advil cold & sinus are for symptomatic relief so it depends on what predominant symptom(s) you want to treat. If you just want to alleviate the mucus and want to sleep then you take benadryl which does not have aching relieved effect. If aching and congestion are the main symptoms, then you should take advil cold and sinus. Wish you have a quick recovery.