You can lower your world level by 1. Work on upgrading your characters and use coop for the highest level domains

Oh thx, I didn't even know you could decrease the World Level. Can you also get op artifacts with Co-Op? Say if someone was AR 15 on someone's world who was AR 45...?

No, you can only join the world of someone with the same or lower world level

Well, you could always attempt domain levels which are lower. Like for example: You could do Cecilia Gardens: Ruins of a Thirsting Capital II (which requires your characters to be level 36) instead of Ruins of a Thirsting Capital III (which requires your characters to be level 59).