After Our Whirlwind Wedding, I Became Both a Green Tea Temptress and a She-Devil

[Planned substitute marriage + flash marriage + devoted to each other + adorable child + playing dumb to catch the enemy + scheming, clingy yandere]

Five million to take someone else's place and marry a powerless, blind, disabled heir to a wealthy family, and look after him until he was gone.

The heroine wanted him to die happy and with dignity, so she acted as both his caretaker and...

But the man not only refused to die, he grew more and more vigorous, and even got back on his feet...

What was she supposed to do now? She hadn't received the final payment yet.