I very much identify with the struggle of lots of different projects. Another thing that's helped me recently is to make it "impossible not to" do the thing I want to do. I managed to solve my exercise problem by hiring a personal trainer. Now I lose $80 if I don't go to the gym at a specific time on Monday and Friday. I've not missed a day in months. I've wondered if with certain ways of arranging my environment if working on projects could be similarly solved in that they require no motivation or willpower because there's no other option.

Cheers, and thanks for posting this question. Just writing out some of my ideas here is helpful since I'm certainly working on this right now too.