HELP! Can't remember the name of a manwha TT

Hi!! I read a manwha while back that was pretty similar to ' i lost the leash of the male yandere'. It had a very similar premise with them both being an isakei manwha was the fl trying to reverse previous brainwashing but i cannot remember the name! ╥﹏╥
What I remember:
- the ml was a bit like a dog trapped in one room
- the fl was originally the villainess
- the fl became a nun to escape the ml?
- the ml eventually became the emperor and lowkey kept the fl in captivity
- the fl was the daughter of the grand duke ?
- she later pretended to lose her memory

I was planning on reading the novel until i realised that i could not remember the name :(( If anyone can help me in any way I would really appreciate it!! Thank youuu~