No, it's a no brainer. Every time you averaged down, and it then dropped, you basically got it completely wrong. Why do you think it is different now?
So far it's been a bad investment, don't make it worse by possibly losing even more money. If the SP recovers, you'll make some money, just possibly not as much. Don't let greed cloud your logic.
In principle averaging down sounds good, but I believe it is a mugs game, often throwing more money after bad.
Good luck with whatever you decide. Obviously this is just my personal opinion.
