OP's context matches item #6 in the Macmillan Dictionary...
yet - used for introducing a word or idea that is surprising after what has just been mentioned
...and could be replaced with something like nevertheless or even so. OP doesn't provide the preceding context, but it should include something matching what has just been mentioned above.
Note that this particular usage has little direct connection to "the passage of time". In this respect it's similar to still, which is more common in current English (OP's example is deliberately somewhat "archaic").
Thus I'm still in love (archaically or poetically, I am yet in love) could either mean I love my partner even after the passage of time (the "literal" sense of still/yet) or the more metaphoric I love her despite all the mean things she does/did to me (those mean things having been previously mentioned).