When I have a hard time getting myself to do anything, I try to think about why I should do something from different points of view at different levels.
What I mean by this is that you need to rationalize why doing something is important to you in terms of its meaningfulness and impactfulness.
For example, let's say I'm a web developer with zero knowledge of building a mobile app. And I want to build a mobile game in ios that doesn't exist in the world yet. When it comes to pushing myself to work on such an app, I remind myself that I want to become a programmer with versatile skill sets desired by many employers.
That will be your high level goal.
However, this goal might be too general and isn't convincing enough for you to keep working on the project. So, let's make your goal more specific. So, in this case, it can be that you are super interested in learning about technical details behind implementing the game whether it is about designing the db relations, software architecture and etc.
That will be your middle level goal.
Finally, if none of them made you want to work on the project, let's dig deeper and make a goal really personal to you. It can be something like you want to build it because you want to play this game but you cannot find anything like it from anywhere else. That will be your low level goal.