I just finished a 15-day study of Ecclesiastes. In conversation with several people I have heard that the Teacher should just be disregarded because the last section, and especially the last two verses, essentially negate everything that went before.
If that were the case, why would this book be in the canon. It should just be thrown away.
I believe the Teacher has some very important things to say. From a certain point of view life is certainly absurd. There isn’t much point to it. You live and you die. You don’t have much in the way of input on the quality of your life and on its length. You live and you die. Most of what goes on in between is absurd.
Read it and embrace it.