I have suffered from cold sores all my life-well especially child hood, and the tips I have are to drink plenty of water, and if the cold sore has developed which it tries to, put tea tree oil on and then cold sore cream (both together).
This will dry it out in like 3 days, 2 if your lucky.
Also put warm water over the area, heat can help once developed. Or when it has developing put cold ice on or happy nose (product in uk) when it is tingling or even developed. This soothes the nose and reduces burning