It seems like you're going in the right direction, but the "angry and upset about it" is not a helpful compassionate reaction. To look at the mistakes we did in the past, to see that we had ignorance in the past which caused us to make wrong decisions, which brought suffering, that's investigating into the Four Noble Truths in retrospect.
We see that this is the suffering that arose, the Dukkha, and this is the cause of it, i.e. my ignorance of the situation. Perhaps we had desire or craving in this instance, we didn't have wise consideration, we had attachment, or whatever it is, that caused us to make a wrong decision. We look at the person who we used to be, and we see the ignorance; we see that we may have been caught up with this hindrance, and we try to have Compassion for the person we used to be.
The key here is to try to see if you've understood that you're different now. You've changed. That's the changing nature of the self. You don't have to freeze yourself into that time and think, "I'm stupid, I'm stupid, I'm stupid," "I should've done this, I should've done that!" You didn't have Wisdom at that time, instead you had ignorance. Ignorance can often arise due to our attachments or hindrances. So we look at the person who we used to be objectively, see they caused Dukkha for the person you used to be and the person you are now, try to have Compassion for that person's ignorance. Then see if there's been a change in our understanding. If there's been a change, then you try to see that change, so you can let go of that hatred or anger towards who you used to be. That person didn't understand correctly how to have Compassion for themselves. Okay, and now you're suffering from it. That's the Law of Kamma. Ignorance brings suffering. So we need the courage to deal with our Kamma, the results of our decisions.
Having Courage in the present helps us not create more unpleasant Kamma to deal with. The wise reaction of having the courage to deal with the results of our Kamma, helps us make the Determination to try to avoid the same suffering in the future. We make a determination to try to understand that this brings this, and brings this, and brings this, investigating into Cause and Effect.
How to avoid it in the future? We try to have Compassion for the person we're going to become, because that person's going to be different to who you are now. That person's going to have to reap the results of your decisions now. So, Compassion for ourselves again. Having Compassion for the person you're going to become, not freezing yourself into a solid entity and thinking that you're never going to change. Everything's changing, everything's changing.
You need to have something to refer your decisions to. Often we don't know how to make wise decisions, because we have nothing to refer it to.
The thing that can help us most is to refer our decisions to the Noble Eightfold Path. That's our way out of Dukkha. If we want to avoid Dukkha, we have to walk the path out of Dukkha. Right Understanding, Right Intention, Right Speech, Right Action, we have to have certain values that we can refer our decisions, too. Core values. Principles. In this case, if we want to walk the path out of Dukkha, it's Buddhist principles, Buddhist virtue which helps us make wiser decisions, by understanding the Law of Kamma. We're going to have to reap the results of actions, speech and thoughts, so we have an inner direction that is firm, so we can make wise decisions. Then we're not swayed so much by external conditions. We know where we're going, even though we don't know the future, we know where we're going. We have a good direction to go in. We steer ourselves in that direction, so it's easier to make wise decisions.
This is bringing up the effort to prevent. Trying to figure out how to avoid the situations in the future. One type of meditation that often is very helpful is to take our Dedication of Intention to develop the Paramis as much as we can for the benefit of ourselves and others, then combine it with Death and Impermanence. When we believe that we may die tomorrow, we become more aware of what is really important to us and what is not. Then we analyze our life to see what we are doing, whether it is helping with our dedication of intention, because we may die tomorrow.
And if we're making decisions that actually don't help the development of our inner direction and are causing problems, then we make a resolution to have more Equanimity in those situations, and put more effort towards decisions that will help with our direction. Making that inner direction stronger so that we can make wise decisions to protect ourselves.