HELP FIND A BL MANGA

so basically I’m going crazy, trying to find out the title of it because I forgot, I don’t remember the main story, but I do know that the main couple ends up happy. But there is a side story where the seme is basically a young master and the uke is a seven but he’s sick. Well he’s kind of sick and then the seme goes on like a journey or something with horses and stuff and then when he gets back the uke dies from his sickness. And then there’s a continuation from this side story where and then next life the Seme is like depressed or something. He feels like something is missing and then one day he stumbles across the uke. I think he was in a field or something and it was like a war setting. I think it’s also a Korean bl if I’m not wrong