Don't let guilt weigh you down. Remain Light as a feather.
Imagine something that you feel guilty about in a new light. Replace those seemingly terrible acts you committed somewhere in your past with positive reconsideration.
For Example: Perhaps you killed someone in a hit and run and you can't seem to get over it. Your always believing the karma will come back to you in the worst way. Well... replace that dreadful feeling by imagining that the victim was a horrible person. In fact what you did was a good thing because the victim's wife and children are received by the absence of their abuser. Moreover, they have the life insurance policy to enjoy the life they've always deserved. Furthermore, this guy is no longer around to deal drugs to children...etc. etc. etc.
You see! It's simple. Alchemists refer to this as transiting and it's know to keep your heart light as a feather. Dive deep into those imaginations until you can actually change the way you feel and vibrate. This will change your life and be the reason you rise above the dreaded "karma".