You've done well anyway to get that far, so you must be handling the bosses fine even if you don't like them. I like the fights for the most part. Without spirit ashes I would not like them as much haha. It's very satisfying to win these fights.
Fire Giant was my hardest fight too. Or took the most attempts, so far. That roll he does got me so many times.
To achieve anything in this game you must be prepared to dabble in the boundary of disaster — Stirling Moss