Seikishi-sama, Sorosoro Watashi o Hanashite Kudasai! ~Youzumi Seijo wa Sodateta Eiyuu ni Shuuchaku Sareru~

After 2 years of working hard as a saintess and as the spoiled prince's fiance, Celia has her engagement broken off and is told by her successor saintess, Michela, and her former fiance that she is useless, leaving her speechless. Kicked out of the palace, she tries to make it back to her home in the woods when the one and only Holy Knight of the kingdom rushes to her side... A former foundling turned yandere Holy Knight and a kind-hearted, abandoned Saintess in an obsessive love story! https://www.cmoa.jp/title/342299/