thanks for the feedback 👍🏻 you shouldn’t need to grind at all to defeat the second boss. Should be doable by level 10 or 11 at the latest.
If you decide to try it again, make sure your gear is up to date. Try using food and crafting accessories if you’re having a hard time.
I’m not sure what your party composition is but try to have a main tank, healer, and 2 damage dealers.
Maximize damage with weaponskills if possible! Sorry to hear about your experience, take care!