Why are we in love "with" someone?

I'd like to learn the etymology of using the preposition with in the phrase in love with somebody. For me it doesn't make much sense because with seems to imply something that is shared by two people, something symmetrical wherein the phrase only states that one person has romantic feelings towards another. In Polish, we say być zakochanym w kimś which directly translates to be in love in somebody, which, at least to me, seems to make much more sense.

Why do we use/What is the etymology of using with in the phrase in love with somebody?

This usage may well go back to Old English, which (ironically) uses "with" for feelings of opposition. For the sense of "with" "after words of conduct or feeling towards (a person etc.)," the OED cites King Alfred's Old English version of Boethius De consolatione philosophiae from the year 888:

Hwi murc nast ðu wið min?

In a modern translation, "Why dost thou frown on me[?]" The Old English Translator translates "murc" to "dismal," so a more literal sense is "Why are you disapproving of me?"

The OED notes that this sense of opposition for "with" was replaced by feelings of mutuality, and in Middle English, as the word took over the Old English mid (with, cognate of the Greek "meta"), it became idiomatic with the object of romantic feeling.