u/Dizzy-Violinist-8409

Hi I've never posted in this subreddit before so i apologize if im not doing this right. I need advice when it comes to my 3 year old cat Maxie. Ever since I adopted her from a homeless person where she had to live in a womens shelter and lived in a stroller and would use the restroom in it and brought her home over a year ago she has constantly peed outside of her litter box and refuses to poop in the box as well. I've taken her to the vet and they just recommended a different diet but still nothing. She has been with my male cat up until jan when we took him back with my parents due to being happier with them than with us in our home. I deep cleaned the entire room etc but the moment she came back from us staying with my parents she started using the carpet again. I use the roxie and rocco mix but she'll just find new spots and likes to go in corners. She does use the box but uses carpet majority of the time. Any advice im desperate.