I’m going to go out on a limb and say that the sin you’re struggling with is pornography/masturbation. Just a wild guess if you’re a young guy.
If I’m right, I don’t think weekly confession is excessive. If you start thinking, “Well, it’s probably not mortal, I can just confess it later…” you’ll be more lax in your struggle to remove it from your life. Even if it is mitigated by the force of habit, it’s best to err on the side of caution and assume it’s mortal, just to push yourself to keep working on it. And since you need to confess any mortal sins before taking the Eucharist…weekly confession seems fair to me.
For what it’s worth, don’t beat yourself up too badly about it, either. You don’t want to minimize, but you should recognize that this is a VERY common sin for men to struggle with, and unfortunately we live in a culture that encourages it. So take it seriously, but at the same time don’t get discouraged.
And yeah, the best person to discuss this with would be your confessor.
If I’m wrong and the sin is something else, well…disregard.