I've tried structure, but it doesn't work when I'm too depressed. It just makes me frustrated when I can't keep up with my schedule. Currently I'm doing the opposite: I just work when I feel like it and otherwise I do other things like work on my own projects or just slack off for a bit. It sounds really lazy but I actually get more work done that way because when I feel like I don't "have to" it takes off the pressure and the anxiety and makes it easier to get up and do something. This is basically how I worked throughout all my university degrees, my PhD, and my work since then. It works very well for me although I have felt like a slacker the whole time. Obviously it only works if you have flexible hours. And I do have to be careful to not fall into the trap of working at nights or in the weekends too much because that leads to instability in my experience.