No time like the present...always the present with every thought and action you take. There is no need to look back at all ever. It's like continually looking back at an accident scene over and over and over. You just have to be willing to say that was that and I am not that. it was one experience. I am a flowing evolving being and I don;t need to freeze myself in time and recreate myself based on that snapshot over and over and over. Release it with awareness of that is what your doing. Also look at it from other angles before you fully release it. See yours elf as all the players involved. What might they have been thinking. Was their impairment. Were they healthy? Could they have been doing their best under the circumstances, etc etc e=etc. Look at it from so many angles you get dizzy and the look at even more angles. WHY/ Because then you will see what the process of beating yourself up has been about. Sheer reliving of ideas and beliefs about an external that you really have no way to control. You can however control your response and move on.
There are 3 main vantage points. Yours...the other persons...and the over all (god, all that is, infinite potential, etc) There is really only one you can do anything about. Yours. ;-)
You can;t feel bad enough to help anyone else nor can you feel bad enough to change your past. However if you shift your focus on what you want and stop looking back at the accident scene, you just may release yourself of the attachment and begin to flow freely in the stream once again, releasing the friction you are creating.
What may help you somewhat is to get a hold of the Abraham stuff especially the new vortex information on video. It may get some aha;'s going for you and get you flowing in this regard. There are enough people on this forum who can be there for you as you release this. You can make it easy or you can drag it out.
Imagine it like code in a computer. Then make it solid code like a pencil. Hold it in your hand. Clench your fist around it. Imagine all of the "he said" and "she said"s that have you wrapped up in it. Every detail. All the side issues. Then observe yourself doing this and at some point tell yourself it's all just a story. A story that site over top of a much deeper you. The you that is aware of the story as just a story. reread that till you reallllllllllllllllllllllllllllllllllllly get it. Its important you do.
Then once you feeeeeel it is just a story sitting over top of you filtering your experience and shaping your life, then drop the metaphorical pencil that held all these limiting beliefs and judgments. Just simply relax your hand and let it fall away.
If the thoughts attempt to haunt then observe them and tell yourself I am not my thoughts. Don't hide from them. Don't attempt to restrict them. Allow them to surface, just don't get on the bus with them .. In othe words don't get into them and build a charge. Just observe them as a dance. They WILL fade. What we resist persists. Allow the dance, just don't dance along.