You've been a long term contributor to the platform and while I don't always have time to read and engage your posts I do appreciate what you do and the discipline in which you do it.

It might be difficult to reason with your downvoter. You could try declining rewards for a little while and see if he gets bored with you and moves on. Unfortunately I don't have much optimism for any other whales to step in an counter his downvotes - but I think that's what probably should be happening in extreme cases like this.