A intense drama where situations lead the ML/SL to hurt FL with strong Plot line

Have you seen Gaksital !? In that the second lead have unrequited love for her but still hurt her because of his situation and also he regrets it .

( I don't like thai Lakron..  even though what I wrote sounds like it,) in gaksital second lead has more than enough reasons to behave that way. Also the plot was so strong. If someone knew such period/ historical/ modern Korean dramas, please mention.  I am also looking for dramas where main lead/second lead avoids FL but loves her secretly