Making a game can feel like cooking a five-course banquet at a michelin star restraunt. Experienced chefs know what to do from sourcing ingredients, preparation, multi-step cooking, plate aesthetics, and serving. We know that not every meal needs to conform to such standards to be enjoyable, nourishing, and filling.
Extending this metaphor further; ideas can be considered the ingredients. Without them, it's difficult to make anything substantial. *SEE VIDEO*
However, also like ingredients; you don't add everything you possibly can to a meal. You evaluate each of the ingredients as you develop a style of what you feel goes together with what else. It's possible your current situation isn't because you lack ideas, but rather you are feeling overwhelmed at all the possibilities while feeling all the expectations for making it somehow magically work. That's a huge burden before you even get started!
There are lots of 'ideas' out there in the world. But it takes a lot of observing and thinking and trying stuff out to learn why it is that certain things work. This is the tricky bit. One could even borrow good ideas taken from various places, but without having space for the concept/s that give reason for the ideas to be there, it can feel inauthentic to the people who browse your work. eg: naively combining words of robot + basketball + eggs to make a game about robots playing basketball with chicken's eggs is empty until you can fill the blanks on WHY this is happening. Perhaps the chicken farmer's robots have been taken over by an A.I. that's worked out it can get more profits to the farmer by filing an insurance claim because of a loophole when the A.I. misbehaves? To answer this why, I've reached into my knowledgebase of information I've passively picked up on. Mid's advice (above) is good. Life experience will give you more ways to fill in the blanks and create deeper and stronger developed WHY.
Also, start small. You have more control over and can understand the impact better with small things. Past me would shirk advice from other people who told me to start small. Small projects feel so inconsequential when compared to the grandiose splendor of behemoths like Dungeons& Dragons or AAA games. Something small can still be impactful! At the moment I'm simply designing a document for use in a game world. Very few people may ever have a use for it, but since I know what I'm going for and why; I know that what I'm going to make will perfectly fit the need for those who will be on the hunt for something like it. The potential that other creatives might see what you've done and feel encouraged to make their own versions may be knowledge enough to cut through feelings of isolation.
Thoughts? Queries? Comments?