My right nostril is clogged, but my left is perfectly clear. the right only runs very watery and clear often accompanied by sneezing. why only right?

Depends: There may be an infection, polyp, deviated septum, or enlarged turbinate blocking the nostril. The irritation and obstruction can make the nose run and trigger sneezing. Always need to, be concerned about watery nasal drainage from just one side as it could be spinal fluid. A spinal fluid leak is a risk factor in developing meningitis. Suggest seeing ent.