ah right, yeah that sounds pretty awful. Having a condition like that can definitely make it harder to focus on things. Make sure to follow the doctor's advice which it sounds like you're doing, keep it up.
Sometimes we can set too high goals for ourselves like "I won't feel good about myself until I've published a book" or something very large, sometimes we need smaller goals that are easily achievable like "I'm going to write for 10 minutes each day", and each small accomplishment can contribute to our well-being and self-confidence.
Or we can punish ourselves too hard for not reaching the goals, "I'm a horrible person for not being able to draw today", and that's also destructive.
I personally find it useful to have a routine that doesn't change every day (at least in some aspects, like mornings or evenings), so I always have some stability in what I expect to happen from day to day. Then you can go to sleep knowing what's going on the next day, which can help with productivity.