If your sins are the same, then you have to ask yourself, “Am I truly making a firm effort to amend my life?”
If we are engaging in an immoral habit that we are truly trying to break, then it is understandable that it will take time, energy, and commitment to change. Replacing bad habits with good ones can be an arduous process.
Sometimes you move a step ahead and sometimes you move two steps behind. God sympathizes with the penitent and will offer a plentitude of grace in the sacrament to aid in conversion.
At other times, penitents will utter the same laundry list because they haven’t properly examined their conscience. Examination takes place outside the confessional before the sacrament. If my sins are always the same, do I take the time to go over God’s commandments and its refinements as delineated by the Church? Sometimes we don’t because we are comfortable with our sins and don’t want to change.
Change is difficult, but not impossible, with God’s grace. “Examination of Conscience” booklets are available in almost every Catholic Church. Just pick one up and read.