What do I do about my cold sore?

There is a cold sore at the corner of my lip and it hurts when I open it. I have been taking meds for it hoping it will help it heal faster but still no luck it's still their. My mother keeps LYING to me she's telling me it's gonna go away by the end of the day but i dunno about that... Can anyone tell me what I can do or buy that can make it go away quicker?