A few days ago i began to get a cold sore. immediately i began getting a terrible cold... diarhea, constant chills, headache, runny nose, sore throat?

See below: This is a problem that requires a face-to-face meeting with your doctor. In that meeting, your doctor will listen to you, perform a throrough examination and possibly order labs or other tests. Based on this information, he/she will be able to tell you what's wrong and what to do about it.

Cold sores: The stress of having an infection can trigger the development of a cold sore. Initial cold sore symptoms can include sore throat, swollen neck lymph nodes, fever, generalized aches & pain of mouth/lips/ effected area.