I had a backache and headache so I was too lazy to do anything but take aspirin and sleep. The moment has dawned to scrap the word "laziness". "Laziness", I know you not! "I know you not" is a poetic way of saying "I don't know you". Saying it that way adds a flourish to your statement. An exclamation mark adds to the flourish. I'm working on reducing your use of present participles. There is nothing wrong with "taking" or "sleeping" but do you see that "take" and "sleep" are more direct and straightforward?

I had a backache and headache so I was being super lazy in everything, but taking aspirin and sleeping helped. It is time to unfriend the word "laziness". "Laziness", I don't know you anymore.