Identify what bothers you the most about yourself. Pick a problem – any problem. Next, identify what is absolutely, positively the BEST way to handle it would be. When that picture becomes clear in your mind, steer your actions in that direction. You can do it even in time increments, if you wish. This is how AA breaks it down for an alcoholic. If you can’t get through an entire day, get through the next minute, then the next, and so on.
If it’s situational, then don’t make a broad, sweeping goal to “never do it again”. It’s too general, and can set you up for failure. Instead, take it one situation at a time.
Have at least ONE person who cares about you whom you can go to for both feedback AND support. You need the feedback, but you will deserve the recognition. A person who cares about you can provide both.