Dealing with guilt

If we acknowledge our sins, he is faithful and just and will forgive our sins and cleanse us from every wrongdoing. (1 John 1:9)
What is guilt?
Guilt is a feeling that we all get when we realize that we have done something wrong, especially when it hurts us or others.
Dr. Albert Ellis, the founder of rational emotive behavior therapy, separates functional from harmful guilt. Often, we jump to conclusions and exacerbate our sense of guilt, paralyzing ourselves. Rather than analyzing a situation correctly and objectively, we see a personal failing as a sufficient reason to write ourselves off completely.
Guilt leads to resentment. (cf. Catechism of the Catholic Church, 1784) Correct formation of conscience avoids this problem.
How do you deal with guilt?
We all make mistakes. Dwelling on our mistakes or recognizing them can turn them into an unhealthy obsession, which we should try to avoid.
It is important to avoid perfectionism. Although we should strive for perfection, we also need to show the maturity to recognize that we will not achieve it. What seems on the surface like a contradiction is actually a key to mental health and happiness.
We have to also avoid awfulizing. When we blow things out of proportion and give ourselves negative credit, we are awfulizing.
Finally, it is important to avoid negative self-talk. The way we speak to ourselves affects the way we think about ourselves.
Good news
Confession is life-changing. In a good confession, we have a lot of important elements to deal with guilt. We face our mistakes head-on, accepting our responsibility. We confess them clearly and succinctly. We get advice about how to overcome and we receive sacramental absolution. We are able to walk out of the confessional guilt-free because God erases our sins.