I don't remember which arc it was nor what the beginning of the arc was but I remember the MC (shou) was a prostitute in a brothel (supposedly because of his family rebellion or something) and the ML (should be a general?) He kind of humiliated MC about this eventho he seems to forgot MC but after he remember he regret it gravely but in the end he was send to defend the border( or rebels?) And was injured but his subordinate used the same idea of claiming the general's death to lower the enemies' guard which was the last string that made MC has to commit suicide against his own heart. (ML promise MC before he depart that he won't make MC wait like before because MC said he won't be able to wait this time.) I hope someone could help me find it because I tried for months from raw to this site please, anyone!
I found it, FINALLY! TITLE: Undying patient (second arc: the amnesiac general and the infatuated madam)