>>30609 (OP)
Finish your work even if it bores you out of the fucking skull. Even if you think your current work holds you back and you have a much better idea now, finish your project and be done with it before starting anything new.
Set a regular time when you work on your project and push against the felling of "I dont wanna" by forcing yourself to work. Ignore how fast your progress is, just progress. Despite that take regular breaks after 1-2 hours.
Take care of your body, stick to your daily personal hygiene. Also be physical active, your body was made to wrestle with nature and if you not satisfy its need to move you will naturally be restless, with just adds to your mental blockade.
Doesn't matter if you make sport or just go outside and walk around for an hour, just really move your body for longer periods at least for an hour once a day.
Keep your house and workplace clean and in order. Also set a regular time for that.
And I have no idea from which country you are, but mine has work safety regulations for working with a computer to prevent long-term illnesses. These might be useful to follow in private.
Actually have an understanding and knowledge about the software and tools you are using, if you don't have them learn from the people who have used them to finish a game similar to what you want to make and learn by directly copying their work as your training.
Make an investment into your project, get the hardware and software you really need. Outsource stuff you can't do yourself.
Introduce little rituals to help you relax during your short breaks, be it how you make your tea, if you start with origami or eat a small fresh plate of vegetables. Avoid eating too much sugar and taking drugs.
Drink enough and watch what you eat and eat regulated, your body has to work to digest stuff and so your food intake has influence of on your work morality. Listen to your stomach, not your tongue and gullet.
tl;dr the majority of mental blockades that stop you from finishing your projects are down to physical needs you body wants to have taken care of, the few psychological ones left can be taken care of by adjusting your behavior.