I've only released one (not too successful) project so far; with another in progress.
I still have my day job and realised that I need to pick my battles right now with which projects I work on.
I personally need to find the right balance between:
1) A good project idea to work on
2) Something doable in a shorter amount of time (short being a month or two?) versus longer projects that may be better, but I wouldn't expect to finish in after hours work
That may not help you too much right now though!
When this happens to me, its usually because I am not sure how to proceed, or I am distracted with what part to work on, or the part I am working on is boring.
Try taking a walk around the block, clear your head, and have a think about what you need to do to ship your product as version 1.0 (MVP / Minimum Viable Product)?
Put together a short list of steps you need to follow to get this done, then start at the first one.
Having a plan of action should give you some energy to work on your project.