Calling all MDs, or Pharmacists need some info on meds?

I recently started sneezing, coughing, runny nose and my throat hurts. so i started taking Claritin because i thought it was my allergies. I cant sleep because i am having to constantly blow my nose so i can breath, so im now exhausted. I want to know if it is ok to take Nyquil. Im not sure if it is a cold or allergies but now im getting an extremely bad head ace. so can i take both? or should i stop one to take another? Thanks.