Maybe you've overdone it a bit and lost track of what originally got you into all of this. If you scatter yourself and chase every shiny thing your core motivation gets kind of burnt out but you don't notice it for a while because all those more superficial obsessive drives keep going once the main engine has run out of gas. Perhaps take it easier for a while until you feel a deep urge to do a particular project.

I got like this after many years of study. So much to learn, I turned everywhere at once and learned many things. After several years I ended up feeling lost - this forest was infinitely deep and infinitely broad, and I didn't know where in it I wanted to go. Though I still had personal identifications that said "this is what you do, you're good at this" and the superficial curiosity to keep learning new things, the deep sense of direction was gone.

The only thing I've found that lets it regrow is to give yourself a break, do something different with your life for a bit. When a deep motivation grows, the shiny things won't distract you from it. When they do distract you that's a sign that your deeper drive has withered somewhat. You can't force it to regrow; you have to wait for it to do that on its own.

Consider this: you mentioned a history of depression. Depression doesn't have to be at the level of a major depression to affect your functioning. And moderate chronic depression will certainly affect your focus. I hope I'm wrong, but you should really go and talk to a good psychiatrist/psychologist and see what kind of help you can get and whatever else you might be dealing with. And don't imagine that it means that you're fucked up in some kind of way: last year 13% of Canadians sought services of mental health professionals. That doesn't include those that aren't getting help for their conditions.

Now is as good of a time to start developing this. All you have to do is just stick with a single task and complete it. Then do this over and over again and it will turn into a habit.