Everybody goes through that to one degree or another.
Some people hit that rut multiple times.
Do your best not to let it get the better of you.
Don't let it be a permanent feeling.
Try to seek out other things to occupy your mind.
Volunteer with different organizations and enrich the lives of others. Help kids, help animals, help elderly, help homeless, etc etc etc. Be an ear for someone who needs company or shoulder for someone to cry on.
Maybe exercise, go for walks, go for drives.
But try to mix things up so you don't make your free time turn into routine and mundane, just like your work/sleep schedule.
Find a hobby. Learn an instrument, take up painting, take up drawing. It doesn't have to be artsy stuff either.
Maybe your house could use some new paint. That's time consuming and can be relaxing as well.
