Summarize:

Guilt is a useful emotion when it is helping us grow and learn from our behavior that has been offensive or hurtful to ourselves or others. When guilt arises from hurting another or having a negative impact that could have been prevented, we are being signaled to change that behavior (or else risk the consequences). This guilt, "proportionate” guilt can be a guide for redirecting behavior and adjusting our sense of what's acceptable and what isn't. For example, if your guilt is from spreading rumors about a co-worker so that you will get a promotion in their place, you'll feel proportionate guilt. If you simply got this promotion for being more qualified and feel guilty anyway, then you are dealing with disproportionate guilt. Forgiving oneself, like forgiving another, can be a difficult process. Steps that are important in the process of self-forgiveness include:  Acknowledgement of the actual hurt caused without exaggerating or minimizing what happened. Addressing the degree to which you were responsible for this harm – there may have been something you could have done differently, but you may not be responsible for everything. Overestimating your responsibility can prolong guilt longer than necessary. Understanding your state of mind at the time of the harmful action(s) Dialogue with the other(s) who were negatively impacted by your actions. A heartfelt apology can go a long way. It is important that you and the other(s) know that you are aware of the damage done and are clear on what actions will be taken (if any) over and above apologizing. Staying guilty instead of making necessary repairs or amends is how we punish ourselves. Unfortunately, this behavior will only keep you feeling too ashamed to take the action that can really help. Making restorative changes means swallowing your pride and trusting that others will be grateful for your work resolving the source of guilt. If apologizing is how you'll make amends, try to avoid justifying what you did or pointing out the parts of the situation that you were not responsible for. Simply recognize the others' pain without the distraction of extra explanations or attempts to revisit the details of the situation. It may be much easier to apologize for an offhanded remark that caused some pain. But when the behavior has spanned some time, say you ignored your partner's distress about your relationship for years, it will take more honesty and humility. Writing journal entries about the details, feelings, and memories of the situation can help you learn about yourself and your actions. Working to improve your behavior in the future is a great way to relieve guilt. Your entries might answer questions like the following:  How did you feel about yourself and everyone involved leading up to, during, and after the situation? What were your needs at that time, and were they being met? If not, why not? Did you have motives for this action? What or who was the catalyst for this behavior? What are the standards of judgment in this situation? Are they your own values, your parents’, your friends’, your spouse’s, or coming from an institution like the law? Are these appropriate standards of judgment, and if so, how do you know? We know that it's impossible to change the past. So, after spending time learning from your actions and making amends and repairs wherever possible, it is important not to dwell for too long. Remind yourself that the sooner you are done feeling guilty, the sooner you can bring increased focus to other, more current parts of your life. Another benefit of using a journal to deal with guilt is being able to keep track of your feelings to show yourself how quickly guilt can diminish once we attend to it. Especially important is making note of how making amends and repairing the situation has changed them. This will help you take pride in your progress and in the legitimate ways that you have used guilt positively.
Recognize the kind of guilt you have and its purpose. Forgive yourself. Make amends or changes as soon as possible. Start a journal. Accept you did something wrong, but move on.