What to do when too tired to meditate but not enough to sleep?

[Manjushri]

I'm trying to meditate now but everything that happens is me sinking into semi-conscious patterns and behavior, even getting up etc. But often times it happens that you get less sleep, but not that low of an amount to just go to sleep. I don't to my practice to suffer because of this, but it does. I do 20 mins instead of 45 and that sucks. 

[PsiloPutty]

Caffeine?