Looking for something like Transmigrating into the Reborn Male Lead's Ex-Boyfriend or How to Survive as a Villain. Basically where they transmigrate into someone who did something bad to the ML, ML starts off hating the MC, MC seems depressed and moody, and MC keeps pushing ML to other people since they think that they're supposed to be together based on the original plot line. And misunderstandings. Many misunderstandings.
Like Love But Not The Decade of Deep Love Love, Expired Muted Living to Suffer Not transmigration or rebirth though, but definitely ANGST at its finest!
It’s Not Easy Being a Master Number One Zombie Wife Where is Our Agreement to be Each Other’s Arch-Rivals? Marshal’s Cannon Fodder Spouse [Transmigration] Well these have the same formula as Transmigrating into the reborn Male Lead's Ex-Boyfriend. Not too angsty, but does leave the ML confused of MC's actions. But if you just want ANGST well... Waiting until 35 Years Old Yuwu +1 Decade of deep love +1 Living to Suffer
If you want too much angst to the point of making you cry, try to read Strategy to Capture that Scum Gong. Although its a QT, it’s really good that every arc will make you want to rip your heart out
Transmigrating into school idol and forced to do business Number one zhombie wife Scum Villain's self saving system