Forgiving isn't making excuses for the person who hurt you or setting yourself up to let them hurt you again. It's just closing the book. The trickiest part is forgiving YOURSELF for having gotten into that situation in the first place - learning how to stop wondering how you "brought it on yourself" or could have "saved" them if you'd tried harder, or calling yourself stupid. People just do mean things sometimes, not because of the people they do them to but because of who they are. People blame themselves for being betrayed because it makes them feel like they can keep it from happening again in the future, but it just doesn't work that way.