Sounds like your approach to work might be the problem. Mix it up. Pick a simple side project and start then finish it. Doesn't even need to be software. The act of finishing it is the important part.
During a funk in my 20s I went into a city Id never been to and spent the whole day looking at art. Thoroughly bored out of my skull. But over the next few days I had so many ideas for things.
Perhaps you need to get really thoroughly and industrial-strength bored?