Dear Athena,
I'm glad previous postings have inspired and helped you in different ways.
It's helpful to remember we give life to ideas in our minds. We have choices to give immortality to positive ideas, hope and dwell on the future which it is in our power to change. We also have the choice to give life to doubt and negative energy which can hold us back from moving forward.
When you find yourself falling into a state of regret, I would encourage you to reframe the situation. For example, consider what you would do next time in a similar situation. Choose to learn form what you didn't do before so that you can let go of the past and retain the wisdom for future reference. I discuss this topic in varied postings on my blog, including "Sudden flash of insight."
"I like what the future holds. I don't like thinking about the past." -John Cale