isn't this considered as a Stockholm syndrome?

You clearly have no idea what Stockholm syndrome is.

didnt the white haired guy forced himself on the mc when he obviously say he didn’t want to have sex ??

Stockholm Syndrome Symptoms:

Affection for or attachment to the abuser.
Attempting to help the abuser.
Distrust of or anger toward those trying to extract them from the situation.
Rationalizing abuse.
Perceiving basic dignity as kindness.
Feeling powerless.

If you've finished the story then you'd know E has none of the above. He's in fact /quite/ aware that T is a scumbag, but he's come to love him for that. They're both a bit wrong in the head and messy, even so, I still think their love is beautiful.