What's done is done

Whenever you feel bad about anything you may have said or done, think...  You may not be alive tomorrow and it will not have mattered at all.  You will be but a memory and everything you tortured yourself for will be forgotten.

As long as you're not hurting anyone, take whatever you say or do as an experience.  What's done is done, there is no turning back.  Time will go on, and so will you go along with it.

People either don't care or forget.  This is your life and yours only.  No one can live it for you.  Opinions don't matter.  You just have to be happy with yourself.  The rest will follow.