Hello DingoBongo. ( If that's even your real name )
I believe I might have an inkling as to what's going on "under the hood".
While this may be too complicating for a young one such as yourself to understand, I would gladly teach oneself the steps to fixing the "problem".
Although I am not entirely convinced that your "problem" is real, and I am becoming more comfortable with the proposition that this may all be an elaborate ploy to expose ones intelligence, I will take the risk ( albeit with much consideration, calculating every single probable outcome ) and guide you to the rewards you seek.
The Initial task involves with your Stardew Valley instance itself. It appears that ones ( yours ) files have been corrupted in some way. Might I suggest you venture to your steam page. Once there, you should navigate to "Properties" -> "Installed Files" and select the prominent option: "Verify Integrity Of Game Files".
If this step does not work, might I suggest a total re-installation of Stardew Valley. If going through this treacherous route, please make sure to create backups of your game files before re-installing.
Ultimately, please consider partaking in the advanced action of pressing the medium sized button, which is most often correlated with the power options of the specified computer. Once this action has been partaken, the next half of the operation might be just as complex, if not more. Please press this same power correlated button once more, and your device of choice should light up. My good friend Roy taught me this technique.
Please contact me if in need of any further details.
Mucho Regards,
Your friendly neighbourhood "Code Inspector" Julius.