I don't think even a 17 yr old can fully fathom the idea of forgiveness, and certainly not with a history like yours. I do wish for you to be able to move on. I wouldn't urge you to forget, but to file this away and allow it to flag your mind if you come upon them in the future...just in case?

The forgetting aspect is good if it's meant to not carry this with you and judge all future ppl or relationships by this experience.

Disappointment is a tough cookie, imo. Try to give some leeway, and when you have contact with them, don't give them all the power. Make your own decisions, and also make a Plan B, so to speak, of what else you can do if they don't follow through.

TC