According to the rate of erosion of the Drama Robe, it will take at least several years to replace his entire skin. Yang Xiao thinks that rather than worrying about whether he'll die years later, it's more practical to consider how to survive until then.
After all, given the frequency with which he enters the Nightmare World, surviving several years is quite challenging.
Both Director Nalan and his uncle have said that the frequency with which he's pulled into the Nightmare World is abnormally fast, several to even dozens of times the speed of an ordinary person.
In any case, Yang Xiao now understands that deceiving the Drama Robe into consuming a Magic Artifact hastily incurs a price, so he'll be more cautious in that regard in the future.
After controlling the Mirror Ghost to give him a massage and relax, Yang Xiao releases it back, because there is still a living ancestor in the secret room.