help please!! Medieval Romance mistaken man takes heroine for slave as revenge

I have looked for years. This is a book set in medieval times, a lord is lost and request shelter in a castle. The lady of the castle is at hime without her brother. She allows the man in the castle however he has hallucinations that she ordered him tortured and when he is picked up injured at the ladies castle, he takes her hostage and makes her his slave and has her remain with no clothes locked. The brother later comes to claim his sister and she chooses to remain with her captor when the two fall in love. Olease help, I have looked and looked but no luck.

Surrender My Love by Johanna Lindsey has a similar plot, it could be the one you're looking for.

Touchstone fairy: Surrender My Love

Yes!!! Thank you so much you made my day, week, month! Years of wondering. Thanks again so much

You're welcome. Enjoy. :-)