Hmm this chapter brings up so many questions, this chapter reminded me of something that bothered me in the last chapter, in that we don't even know if his deceased wife and him had a night together (normally i'd not say anything, but last chapter amelia directly mentioned "they must have because she was pregnant" even though she was a spy sent by his uncle, this is a red flag because if a mangaka points something out, it usually means something, especially if the ML went out of his way to say she was a spy).
Then in this chapter was the uncle himself, who comes off as less villainous than i'd have expected, while mentioning his wife from behind (a surefire red flag, maybe it wasn't the uncle after all, but the aunt who wanted the family estate, ML did say his uncle was a quite virtuous man unlike his father, it's entirely possible that the aunt is trying to cause a rift, and in shoujo the villains are usually female, excluding yandere's).
Finally though the ML's love might come off as sudden, it's probably not sudden (though even if it was, it's not like this doesn't happen all the time in manga and sometimes irl), he probably is just now realizing it, a common trait in manga is to do something to keep someone close only to later realize it was because your romantically interested in them.