If we went with the ch.70 original ending, then no, Kyungsoo was actually the sane one, leaving Yule and letting go Dong-Hyuk. If we went with the "what ifs" endings with Geon, Dong-Hyuk, and Yule... then yeah, he is far gone. Choosing to end up for the rest of his life with abusers and rapists. He pretty much doomed himself.
("Good End")Shiki after achieving his goals starts shutting down cause he's done and he has come to the conclusion he has no more purpose in life. Akira gets stuck with him and ends having to take care of him for the rest of his life. (Bad Ends) Shiki accomplished his goal but with an extra benefit giving him a new purpose (here it divides into 2 ends) 1st end he takes Akira along with him to become his commander while Shiki begins his dictatorship and begins his plan to take over Japan. 2nd end Akira goes with Shiki in thus one to Shiki begins his tyrannical rule but this time his and Akira's love becomes hecka twisted and Akira becomes kinda sex crazed. Intentionally seeks out "willing" guards to become his one night stands. Shiki every time he finds out about what Akira did would go and kill off everyone who touched Akira while he was gone. Then fuck Akira like crazy cause he knows Akira is doing this cause he's lonely and wants shiki's attention.
Everyone is talking about yule being fucked up, but isn't kyungsoo is the one who's super fucked up( ̄∇ ̄")