I think that leaving behind the feeling of guilt is very important to be well here in the present time , that way tomorrow you ensure a good start of the week , a great awakening for after a good shower to enter the work without haste with all the calm in the mind that is possible that soothes the soul.
I always say that a good or bad day has only 24 hours, then we will see without so much anxiety for tomorrow Mr. @galenkp
Guilt and regret are two different things, but sure, people feel guilty also and carrying that forward forever isn't always the way to go. It's difficult to consider how one may feel in the future though, and so people live life in the present and don't think much about future regrets. Maybe that's best as one needs to get the most from the present. I don't know, I'm no expert in the matter.
You are right, everything that is done when we focus on the solution in the here and now without excess of future, in the daily and constant work of being resilient and resistant to difficult situations is the formula to improve and avoid it.