He was consumed with painful guilt of breaking Leah's heart.
Leah was devastated, but she hoped for the future, but Sam told her to give up on him.
He had already met Emily several times, and liked her very much.
However, when he met her for the first time after he phased, he imprinted on her the moment he looked into her eyes.
She was horrified when he explained that he had broken up with Leah in order to be with her.
He obeyed when she told him to leave, but didn't stay away for long.
Eventually, he told her all his secrets and even phased in front of her.
Sam then spent two days waiting for Emily to return to her home in Neah Bay.
He forced himself to stay away while she was with Leah, determined to keep from hurting Leah anymore than was absolutely necessary.