Constantly reliving sins already forgiven

"...my problem is I am constantly reliving my sins of the past two decades...Everytime I confess almost immediately out of the confessional I remember more stuff.... I feel typically worse after confession, like no matter how hard I work I can never truly be forgiven."

Forgiveness is independent of how hard you work. Instead, it has everything to do with how God is working in you.

You were already forgiven of the sins you come to remember after confession. It may very well be God's desire that you continue to remember your past sins, in bits and pieces. Think of your "remembering" in this manner as God's way of giving you the gift of sorrow in small doses so as not to overwhelm you with such sorrow that you fall into despair.

Also, remembering our past sinfulness is catechetical, and helps us to not repeat such errors in the present. God is teaching you and bringing to your attention these sins, so that you may become more devout, more detached from affection to these and even venial sins. Perhaps if you understood it in this light, you would understand that it is not a sign of hopelessness, but is indeed a means of continuing the gift of contrition which God himself is giving to you.

The Lord does not give contrition to those whose hearts are hardened. When you are made aware of past sins and are made sorrowful for them, thank the Lord for such a gift, because instead of hopelessness, it is a gift of hope.

PS. I had 25 years between confessions, so I understand what you are going through. I bless the Lord for the remembrance of my past sins as they help me to understand where I've been and where I am. Such memories are a holy grace which continues to draw me closer to God and away from my past wickedness, and to pray that, with God's help, I may sin no more.

God bless,

Dave