Is there an easy and fast way to take care of cold sores?

Anti-herpectic. Cold sores were caused by herpes virus. So, oral Acyclovir treatment is a classic appraoch. However, recurrence is common. So "get rid of it" is a tall order.
See a dentist. You can't get rid of cold sores, but you can control them. It might be something else, so see your dentist or physician for a definitive diagnosis and treatment. Til then, keep the area clean with warm water rinses. Sores can sometimes be contagious so don't touch the sore with your finger. If it's painful to eat and drink, try bland foods and beverages.