Epicurus doesn't say the "joy" outweighs or conquers the pain of his condition. The word used is Ἀντιπαρατάσσομαι (antiparatassomai) which conveys "holding one's ground against, and in drawing up troops in battle order, side by side, ready to do battle against an enemy."
There is NO τοῦ κακοῦ (“evil”) in the manuscript! That’s an addition…
Great points, Don, thank you! I have noticed that Perseus has been slow again lately, I wanted to recommend this site, which I just started using.