Every morning my nose is plugged up, & i expel a lot of mucous when i brush my teeth. later in the day, i'll sneeze & ache all over. what is it?

Many possibilities: Usually this type of problem has several influencing factors. Allergies play a part, diet and inflammatory responses contribute. A reason found commonly is related to candida (yeast) overgrowth. If appropriate, you may need to go on a "yeast starving" diet, which initially has virtually no carbohydrates, which yeast thrives on. William crooks, md has published guides for this. Also may need meds.

Allergies?: It sounds like typical seasonal allergies with the possibility of a sinus infection.