Although you flirted, a generally healthy, trusting relationship should be able to weather some mild flirtation. Is she that jealous or was it considerably more than mild flirtation? I'm not 100% certain you own your full role in this, as you still reference that you were denied attention and tricked into thinking she was cheating.
Should you reunite as a couple, you will need to pour a lot of effort into building trust. I recommend a couple's counselor if this is a serious commitment. I have found that the single most genuine and effective method for making amends is a humble, heartfelt question: "What do I need to do to make this right?" Listen intently and nondefensively and commit to change. As for a song, I recommend "All Out of Love" by Air Supply.