Maintaining good mental health is quite a task for anyone in recovery. However, I believe one should establish some routines that also do not convert them into robots. This should be things that one enjoys. Personally, I enjoy outdoor activities and they give me fulfilment. I convert this fulfilment into energy I can use to maintain a good mental health. I also try to participate in sports weekly, I feel like the sweat is good for me.
Reading a physical book is lso quite fulfilling. I would advise you read something you enjoy.