How many miles/kilometers do you have on that engine? It sounds like your engine is doing exactly what you said “eating oil” or rather burning it. I attached an image of bad spark plugs. Did your old ones look like any of them? Also look at the new ones you put in. Usually when an engine burns oil it leaves a white deposit on the spark plugs. When you accelerate hard, glance into your rear view mirror and look to see if there is any smoke behind you.