To Marry is Madness by Ashtyn Newbold

Never make a bargain with a madman…no matter how handsome.

Abandoned by her family because of a well-kept secret, Miss Charity Oakley plans to live out her spinsterhood alone in her family’s country house. But when her mysterious illness begins to worsen, she wonders just how long she will live at all.
When Mr. Sidney Delamar, a presumed madman and mischief-maker finds his way to town, Charity does all she can to avoid him. What she didn’t expect, however, was to find him begging for refuge at her door. Striking a bargain with a madman is a dangerous task, but so is refusing one, especially since Mr. Delamar offers something she desperately needs in return…

To Marry is Madness is a sweet and clean regency romance, and can be read as a sequel to An Unwelcome Suitor by Ashtyn Newbold, or as part of the multi-author Supposed Scandal series.