I can suggest ways to victory, but no victory ever came easily or cost little....just sayin'. This is where you dig deep and rid yourself of guilt, woulda/coulda/shoulda, and make a grownup out of yourself in a way you struggle with at present:
Faith
Confession
Journaling
Volunteering/mentoring (the latter requires introspection, self examination, drawing conclusions from experience, and then being able to demonstrate the logic behind what you propose that others do/don't do)

You can't let your past go because it is untidy and unfinished. Finish it. Put it to rest once and for all, let it go, and be the improved person you can be for having lived your experience with it. Look at it this way: if you were to die in your sleep tonight, would you like it to be as you are today, or as you would be tomorrow had you awakened with a clear conscience?

One last statement from me: In Christ, all is forgiven. If you repent, and are in love and in charity with your neighbor, then you have served your purpose, the purpose we all have in life. I'm going to go out on a limb and wonder if you have lived the life of a hedonist because of your artistic bent (this is just on the basis of likelihood, or of probability, not an accusation or a judgement...certainly not from me). If you are sick of that orientation and would like something more pithy, more personally demanding, then look on Christ. The way to deal with your sordid past or mistake is to turn your back on it. Make it a thing of your past, not of your future. Turn to Christ.