As an artist it is easy for me to work for days on end without much contact with the outside world - or with an internal virtual one, it is just me and the work that must be done.
And as with a lot of other art, it's experimental in nature. You don't know the outcome, it's risky, it's difficult to plan for.
The unique situation and implementation of your creative problems, nebulous goals, along with the large stretches of time you are not exposed to any new stimulus and the unknowable future may make you think you simply cannot do what it is you are required to.
You hit a dead end.
The answer is always that you shouldn't be doing it alone.
Not in a 'get your friends and loved ones to help' kind of way (though that does help), but in a use what others have already put into the world kind of way.
Use the leverage of the digital age to seek out answers to your problem. Just start down the rabbit hole and you will emerge with new understanding and solutions.
Gone are the days of the punished, emotional artist - now they can google their way out whenever this feeling emerges. It has really changed the creative game.
The world is so large and far more intelligent than any one person, use any resource you can, stand on the shoulders of giants, steal like an artist, be respectful and appreciative of others' work. It's there for a reason - your responsibility is then to apply it.
You're job is to be the crucible - to add smarter people's material to your potion. Eventually you will make gold.
Don't do it alone.