How much should I regret my mistakes?

I think there is healthy guilt and unhealthy guilt.

Guilt can move us to set things right with the person we have wronged, to make amends.

Barring that, guilt can encourage us to amend our ways so that we do not do the same thing again in the future.

Or, guilt can lead to self-reflection so that we come to understand ourselves better. It can even lead to a major change in our priorities in life.

Guilt might lead us to be more understanding toward others when they have engaged in similar wrong-doing, in that we can understand them better, and maybe have constructive conversations which would be more likely to get them to improve than a scolding rant would.

But, guilt can also be something that we merely get mired into, and I don't think that does anybody any good. It is one thing to say, "I have done bad things." It is quite another to say, "I am bad by nature."

If your haunted by your mistakes .
There's a voice of a person's name going on inside your mind that you have to makes amends too .
That's what's haunting you .
Your never free otherwise

Learn from them but don’t harbour too much guilt over it. Imagine the waves from the ocean coming up over you and sweeping the guilt and bad decisions away from you back into the ocean

Always learn,move on,try not to make same mistake

That's something you must search within yourself.

Guilt is a useless emotion. See it, fix it, move on. Unless you do it to me, in which case I want you to suffer guilt from now on.