Thank you to all for your input. The fact that some of you are doing well is very good to hear and also very encouraging.
I would have to agree that overall Adsense performance will vary according to niche. In my case I can say that my niche falls under the non essential category, therefore is prone to volatile demand changes in time like these. In recent weeks I have also given much thought to the rise of ad blockers, which I suspect have been eroding my ctr over the past three years or so.