Dealing with kiddo's depression and split household

My 14 year old has been struggling with depression and our split between two houses is making it worse I think. She doesn't want to go to her mom's house some weeks and it creates drama. Her therapist says we need to work together on this but my ex just wants me to force her to go per the custody order. How do I balance following the agreement while also supporting my kid's mental health? This is really tough.