Tiredness is a continual problem for me.
For me there is no way of getting it to "go away" so I just have to work on my attitude to accept "this is tiredness" the mind is like this (see the features of tiredness like lack of clarity and focus, thoughts drifting off) and accept that that a tired mind is like this.
It's still hard because it feels as though this "isn't meditating" but being aware of mindstates, their nature and how they feel - also seeing that they are not you or yours - I suppose is a pretty important part. I still find it annoying, but thats yet another thing / reaction of mind to see.
Here where a thousand
captains swore grand conquest
Tall grasses their monument.