Our mindset after confession should be that we would rather die than sin again. It's lucky that God loves us more than we do ourselves, though, else none of us would be alive for the following week's confession.
St Rita's prayer was for two unrepentant sons resolved on murder. A last resort, having begged and pleaded with her sons to change course. Even then, she left the choice to God.
No addiction is impossible to overcome and before anyone gets to the point of praying for their own death (or anyone else's) begging God to heal the addiction or at least to reveal its purpose in that person's life would be the way to go.
Speaking to a priest about the problem would maybe be a better idea than looking for answers on a message board.