If you truly love her, and don't want to miss her, you must have a gut to tell your past affairs to her now. You must tell the truth and convince her that was the past and nothing to do with your bright future together. Of course she felt hurt right now, but that's the reality. And you have to move on. You must be honest yourself and with her too. And Move on.

If in return, she won't trust you and want to click time often bout that past ..  Eventually, You got to consider to leave her as well ...... !

Good Luck !
AN