Why does George say he wishes he had never seen Eliza in Uncle Tom's Cabin?

George is in an especially despondent mood after the savage whipping he's just taken from his master. He's an exceptionally hard and diligent worker, but that cuts no ice with his master, a cruel, vindictive man who resents George for being so much smarter than he is. To make matters worse, George's owner has threatened to sell him down the river if he doesn't marry another slave.
George is so saddened by his condition that he opens his heart to Eliza and tells him that it's at times like these that he wishes he'd never been born. He also tells her that he wishes that Eliza had never laid eyes on him, because then she wouldn't have married him, and if she hadn't married him then perhaps she might have had a chance to be happy in life. As for George, he's made his mind up; he's determined to escape from his present misery and head up North to Canada.