friends who RUINED the friendship

I’ve read an epistolary (whose title I have already forgotten) where the leads started off as friends, developed feelings for each other, and ruined their friendship by dating, only to realize that it was never going to work out due to incompatibility, ultimately ruining their friendship for good.

As someone who has read a fair share of stories with the friends-to-lovers trope, the conflict is usually about one party being afraid to confess, someone suddenly returning from the past, or something similar. I would like to get some recommendations with a similar plot to the one above that’s not necessarily an epi :) Salamuch 💗