To me it looks like he's looking for some answers and confirmations from Seungeon's side before ultimately leaving him. He keeps thinking about how Seungeon will get married to some other person. It sort of feels like he thinks he is undeserving of Seungeon's love. He also mistook his remaining love for Seungeon as "anxiety" because honestly, if I experienced all that bullshit he did, I wouldn't believe I still love him, either. His situation is completely understandable and I'm sure a lot of people would react the same way as Min Ji Wook did to... All the sh** that happened to him
I don't know what's going on anymore