24 F $0 in debt Credit score : 781 in August 2022 Credit Score: 711 in August 2023

As of August 2022, I added my then fiancé as a authorized user on my Chase Sapphire Preferred card. It was abused. He would pay me back 1/4 of his charges monthly ontop of interest has ruined everything. I have fronted 3-4k monthly to cover the debt but I have officially hit rock bottom. This caused me to kick him out but now I am $15,000 in debt from him and is growing monthly. My credit score is going down statement by statement. I am in such emotional turmoil from this as I have worked my ass off to be 24 years old sitting near an 800 and $0 debt. I have looked into loans but i’m still facing a 12-13% apr. I know this is better than what Chase currently is giving me but It makes me sick I am in this position from someone. Please, any advice on what is best to do? Thank you