You should go over all of your side projects and catalog the point in the project and the reason that your interest fell off. Maybe you'll find a common theme s

You should go over all of your side projects and catalog the point in the project and the reason that your interest fell off. Maybe you'll find a common theme such as, "built prototype, now need to add a ton of (tedious) features". Or "built MVP, now need to polish the design and write marketing copy". If you're able to find such a theme, it may suggest a path to success. For example, if you always get to a functional product but quit when it's time to promote, you may want to find yourself a bizdev partner. Aside from that, the only other thing I'd say is that you should find yourself a partner. Things turn out much better when you've got someone to work with.