How a AmE native speaker would indicate that they have slept less than usual / needed hours and they had to sleep more, but for some reasons they didn't do that?
I have some offers here; could you possibly let me know if they work naturally:
I slept less than usual.
I have lack of sleep.
I have sleep-lack.
The latter two sentences are direct translations and exactly what we say in our language.
For me, they all sound grammatically and idiomatically correct, but what makes me fall into doubt is Google Ngram null result.
Best Answer
We can say:
I am sleep-deprived. I haven't been getting enough sleep. Lately I've been sleeping far less than usual. I am badly in need of sleep.
Your 2nd and 3rd examples are not idiomatic.