Stress/anxiety is one of the top reasons to be exhausted and tired and have a lack of motivation. I don't think there's anything to worry about: however there are things that can make the exhaustion and tiredness worse that you could have a look at to make sure nothing else is contributing to it.
-If you're on any anxiety medications a lot of them have side effects of exhaustion/tiredness
-If you're low on your B12 a side effect is most always exhaustion
-Sometimes if you're not fuelling your body correctly and eating properly your body will be unusually tired because it's not getting the proper nutrients it needs.
-Make sure you're getting enough sleep (but not too much - because that will always make you tired).
-Maybe go get some blood work done and make sure all your levels are good just to rule out anything being too low that would be contributing to this.
I'm sure you're fine and it's definitely your anxiety that's playing a large part in the exhaustion, just try to fuel your body right and double check and make sure everything going on inside you is at the correct levels