OP, my heart goes out to you - sounds like you had some horrible experiences and there is a lot weighing on your mind
I went to Catholic school as a non-Catholic in the 1990s and there was an element of emphasis on sin and guilt that was pretty heavy. I am probably dyspraxic but was never diagnosed and I was made to feel like my inability to hold a pen properly, wear my uniform neatly or pass my cycling proficiency test were moral failings....
However I think until very recently there was a lot of fear-based teaching in Catholic schools which at times strayed into superstition and paranoia, and an excessive emphasis on sin without the other side of the story - redemption and God's unfathomable love for us. I also think that there were nuns, teachers and priests in previous generations who had a mean streak, who were misogynist and who had absolutely no business being in positions of authority over kids. There was also some straight-up terrible catechesis.
However... Fast forward to 2026 and I have actually converted to Catholicism!! (A story for another post) Pope Francis was my biggest inspiration and I think he has ushered in a much more compassionate variety of Catholicism, and the wonderful Pope Leo is continuing that legacy.
During my RCIA course as I prepared to become Catholic I never once felt that same morbid obsession with sin and guilt as I experienced at school on the 1990s. Of course sin is a very real thing and we must guard against it and repent of it. That has not changed and never will. But the hellfire and brimstone has been totally absent from the conversation. Confession is now referred to as the sacrament of reconciliation and the emphasis is on rebuilding your relationship with God if your actions have caused you to move away from him. It's not a tick box exercise in disclosing what a crappy person you are in order to avoid damnation. When I came out of that confession box for the first time the most overwhelming thing I felt was God's love for me.
As a previous posted said, I recommend looking up the Sycamore course and any videos by Father Stephen Wang. He is really good at explaining the basics principles of Catholicism and I think he might have some insights for you that will put your mind at ease.
Sorry if that was a bit of a ramble but I think Catholicism in previous generations had some nasty undercurrents which were cultural and of their time. I think if you came back to the church now (at least my one in London) you would find a happier and lighter environment. I know it's brought me a lot of peace.
Wishing you all the best in figuring things out. Remember God loves you 💖