My best guess is that you're not procrastinating on doing the FOSS, but that doing the FOSS would be procrastination, even if you did it successfully. People who work on FOSS full time seem to me to know why they're doing it and how they got there, and why they're running out of steam. Things like, I did it adjacent to being in school, or for my job, or to fix a bug for some game I like playing that wouldn't work anymore.

The way you've formed it is more like "I'm an athlete in a position to devote myself to full time to sport." than the slightly more plausible forest gump "I just felt like running." It's ok to have big almost irrational dreams or hobbies, but you have to at least be very specific at whats being attempted before going to the time management well. If I'm a doctor I'm not giving a kid an adderall prescription because he and his mom say he's having a hard time with his yoyo practice, I don't care if he's some yoyo social media star or not.