Great question!

First of all, you are experiencing these feelings because somewhere, someplace inside of you, you are being conditional in your thinking and beliefs. When you experience a situation and feel guilt/regret, your subconscious is making you aware through the emotion you are feeling, that there is something you are judging about yourself. If you push this emotion away, you lose the opportunity to deal with it in the moment, and you will have to re-create the experience all over again in order to allow the emotion to come up. You have to be unconditional with yourself (don't judge yourself for feeling these particular emotions) so you will allow yourself to feel these emotions. Then as they come up, you can use tools to diffuse the emotion and replace the conditional emotion/thought with an unconditional thought. Once this occurs, you will not need to repeat the experience again because you have just permanently replaced your conditional thought with an unconditional one.

Find more about the tools used to diffuse your conditional thoughts.

Find out more about this personal development material.