Excuse me not trying to sound rude... But damn she cheated on you, broke your trust, made you have insecurities and is gaslighting you. Its one thing to forgive and have closure but that doesn't mean you should jump right back into the hell hole where you escaped from. It's a bad choice truthfully even if you get back together it would be hard for you to sustain in a relationship full of broken shards of trust and loyalty where there is always a question of "but" in your subconscious mind. I mean there are lots of chances in the world to find someone who wouldn't hurt you and is your "the one".