Twilight isn't so oblivious to his own feelings after all. He just has no other choice but to do everything he can to convince himself that what he feels are merely carelessness or failings on his part.
I think the recent chapters mirror chapters 13 and 14 of the manga. If we go back to chapter 13, we'll remember how affected he was by seeing the genuine affection between the Briar siblings, who, despite their imperfect relationship, share a genuine complicity and affection. Things that Twilight no longer remembers how to feel, and this made him realize that he felt envious of that. He not only envied them, but unconsciously tried to include himself in that environment.
The day after this incident, Twilight tries to test Yor to see if she was suspicious and fails miserably. Perhaps it was an attempt to convince himself that she wouldn't affect him, and in the end she did. He felt guilty for doubting her and was hooked by her when she said she was "grateful to have married him." However, in the same chapter, Frankie makes a point of reminding him that he is a spy and that people like them can't let their emotions take over, as it can be fatal.
Yor's relationship with Yuri reflects what Twilight desperately desires deep down: love, affection, and companionship. Twilight is hungry for love, and that's precisely why he put himself in danger when he fought Yuri. He lacks the courage not only to hurt Yor, but also to shatter the image he saw in chapter 13. Because if he did, he would also shatter the image of his deepest desire. Not killing Yuri wasn't just for Yor's sake, it was for his own too.
"If she lost him, she would lose the motivation to be married to me. And Operation Strix would suffer because of it." The "Operation Strix" he talks about so much is himself. He uses "Operation Strix" in place of "I, me, mine."
And it is in this thirst to belong, to be loved and to love as well, that he begins to mold himself so naturally to the Forgers, to Yor, and even to Yuri too.
Twilight's subconscious adapts him to this life because, in the end, it's what he desires most. And that's why he's constantly blaming himself, stressing, and collapsing. Because what he is at this moment (a spy) no longer makes sense in his life, but he's only known this life. He programmed himself to be this way, but he's being reprogrammed. So it's not like he's completely oblivious. He understands his situation, he knows there's a specific emotion for Yor, but he can't discern WHICH emotion. He doesn't know what it is to love someone, so he's always berating himself for not being perfect enough. He's failing. Yor is constantly telling him that he doesn't need to be perfect, that he also needs to look at himself and validate himself. Totally the opposite of what he's always believed.
