Don't worry he will treat him better. But I must disagree with you on one thing. Yes, him arresting Dr.seok and dragging him into a room full of corpses before putting him in the basement of gwacheon shelter sounds bad, but Dr.seok was doing thats that could get him killed. I guarantee you if ANYONE ELSE found out wha he was doing they would've executed him on the spot (maybe not major lee and major yang but you get the point). Showing him the corpses was his way of telling Dr.seok the garden of eden was full of shit and arresting him was his way to get him to stop investigating and getting himself in deeper shit with the higher-ups. It seems harsh (and as much as I do want to deny it, it did indirectly lead to him getting bitten which I will once again advocate for the fact that Major kwak had no control over it), but at the end of the day he did all of it because he had feelings for him and not because he was loyal to the city.
Yes, he could've been like "stop doing that" but he already did, many times and since the government already revoked his rights to information, they were already suspicious of Dr.Seok and it wouldn't do him any good to keep investigating. Again, what he did was harsh, but with the amount of options Major Kwak has, he didn't really have many other ways to protect him.
as much as i dont wanna blame major kwak because i know he did what he thought he had to do.. i want to see him regret what he did and then like idk maybe crash out? and then when dr twink wakes up, major kwak is gonna have to be the most understanding caring loving bf as he should be to him and realize he shouldnt have done the dr like that (arresting him and stuff)