My Eyelid Has A Huge Bump That's Swelling My Eye

My eyelid has a huge bump that's swelling my eye shut and starting to become painful. At first I thought it was a stye, but I've come to realize that's not what it was and I didn't have the symptoms of a stye. The bump is really big. How can I get rid of this bump? It may even be a insect bite, such as a spider.