"The soul that will go to confession and receive Holy Communion shall obtain complete forgiveness of sins and punishment." Diary 699. This is like a "second baptism," and if we were to die we can hope to go straight to Heaven!
A Polish Cardinal has said that confession during Lent, suffices to receive this promise. If you haven't gone yet, go ASAP, but be sure to be in a state of grace when receiving communion and unite yourself to the Lord with great trust!
The church has also issued a plenary indulgence on this day. More can be read here: https://www.ewtn.com/devotionals/mercy/indulgence.htm
"Let no soul fear to draw near to Me, even though its sins be as scarlet." Diary 699. In confession Jesus takes away our misery and replaces it with His Mercy!