Plus he also starts to remember some of the memos but with pilwon not the ones he had with dooshik so now he thinks pilwon is dooshik he doesnt remember pilwon's name and face  therefore he thinks that the memo he spend with a person (that is pilwon) is the same man he is happily living with (that is dooshik)

I don't think they die- 
Joha losses his memo even dooshik and then when he starts to remember he ends up remembering pilwon so hence he now thinks that dooshik is pilwon he isn't scared of him(dooshik) yet coz he remembers the happy memos with pilwon not the bad ones so yea....