I have this eternal blackhead. What is it, really?

it sounds like it's just a persistant spot that's irritated by the fact your skins oily, try using an un-perfumed face scrub like St Ives and may i suggest buying a face sauna kit, they're not expensive and the heat will draw out the oil in the skin. I had a similar problem and when i used the face sauna i found that my skin became less and less oily.