My dear brother, it sounds like you are suffering from an affliction that tends to haunt many of the saints - scrupulosity. I suffered greatly with this burden when I first came back to the Church. Then my confessor told me to stop beating myself up about my failings and concentrate on how much Jesus loves me. He told me that the Father so loved the very idea of me (even with my weaknesses) that he caused me to spring into being. Our Father loves you that much, too. Jesus understands your struggles.
One thing you may want to consider is something that was discussed in This Rock magazine: “The Catechism explains that one commits only venial sin when he disobeys the moral law in a grave matter but without full knowledge or without complete consent”. CCC 2352:
To form an equitable judgment about the subject’s moral responsibility, one must take into account the affective immaturity, force of acquired habit, conditions of anxiety, or other psychological or social factors that can lessen, if not even reduce to a minimum, moral culpability.
You are not alone in your quest to please God, though none of us really can. Only the Son truly pleases the Father. So it is only the grace that comes from Jesus that makes us pleasing to God, and it is only through faith and faithfulness that we attain that grace.
God does not demand success; He only asks for faithfulness. Faithfulness means we try, but we confess that with all our trying we will never succeed. So we cast our burden upon the Lord and trust that He will carry us, as He has promised.
Grace to you, brother.