Someone who would throw your trust back in your face is garbage.
Far as I can tell, the three stages of baggage are: sadness that someone you trusted chose to hurt you; horror that you chose to trust someone so unworthy; fear that your judgment will fail you again.
You get over the betrayal by chucking the baggage — piece by piece. Accept that trusting always comes with a risk of abuse; that shame always rests with the abuser; and that the abuser wins only if you keep blaming everyone else — future partners, friends, Alan Greenspan, yourself. Let hindsight teach you the signs you missed that your boyfriend was not a nice guy. Then, when you’re ready, let yourself trust again.