Can a Person Be Truly Repentant While Simultaneously Having No Hope They Won’t Commit That Sin Again?

Questions about whether a person can be truly repentant while simultaneously having no hope they won’t commit that sin again, how we can “let the Lord work in us” and know he’s truly Lord in our lives despite our continuing sin, and whether mixed motives make otherwise good actions sinful.

• Can a person engage in genuine repentance while simultaneously having zero confidence that it will be the last time they commit that sin?
• How can we know if Jesus is truly Lord in our lives? Aren’t we always falling short of God’s standard? I’m trying not to “try” and to “let the Lord work in me,” but how does one even do that?
• I seem to always find some kind of non-virtuous reason for why I’m doing anything, including reading the Bible and going to church. If whatever is not from faith is sin, can mixed motives make otherwise good actions sinful?