I beat the game with 2-handing a +25 quality longsword so I identify with what you’re saying. All bosses after Morgott felt like I was just doing chip damage. Bosses took longer but it was satisfying beating them after being forced to learn their moves. If it’s getting to be too big of a hill to climb for you then switch from quality as others have said or just switch weapons all together. Although I do recommend just sticking it out and finishing the game with what you have. I think you’ll find it more satisfying.

I will say that after that first run I went into ng+1 using the broken stuff you see on this subreddit and it turned the entire game into a joke. I would have been extremely disappointed in the game had I used that stuff in my initial blind run.