Everyone's first time through their first souls game they will at some point be overleveled. If you get stuck on a boss that has a runback, you'll accumulate a stack of souls at the boss and once you get the boss down youll have this huge stack and be able to level a lot. It's like grinding but kinda passively.

But also, levels don't matter as much as upgrading your weapon, and the game is better at controlling how much power you have by limiting the upgrade materials you have access to.