Wisdom says broken heart is cured by another heart -- a new love definitely gets you over break-ups.
While memories need not be gone. I actually consider it pretty bad. The only thing to let go is attached pain -- one that is rooted not with the memory but later problems and events. That is worth working on, to detach all these contaminating factors, and gain back the memories as they were, be able to feel that joy, excitement, whatever in the original form.
Took advantage? Come on now. Everyone is his own master. You provided everything of your own free choice. And well done too. It's pure poison to think like that. Were you unhappy with giving? If you were, why you did it? Blame yourself, for not listening to yourself, and ignoring real intentions. Or if you were not unhappy, as normally happens, there's no reason to change that after-the-fact.
You know the basic joke: a lady goes to the shop, and pays with a $100 bill. The keeper looks at it, then gives it back, saying it's a counterfeit. The lady starts shouting "Help! I was raped!".
You were left after 3 years, it is sad really, but that part really can't be changed. All you can work is to eliminate the clouds and recover happiness backwards, and obviously forward. And if you can finally reopen for love, you can find another.
It's a hard life but it's in its nature, and can be just embraced.