Read Keynes. Not works on Keynes, not Keynesians, nor indeed pretty much anything in economics written after about 1970, because more or less all of it is error, propaganda and mental malware. Just read Keynes himself.
If you still have questions after that, Uhm, sorry, that is as good as it gets. Most further readings will decrease, not increase your understanding, because obscuring the truth is why they were written.