another annoying saturday morning in my ship arena

Are you, by any chance, in the chat of your shard?
Chances are, if you are not, that your shard is not at all more competitive than the rest. But if you climb several hours before your PO and kick people back 1-2 hours or even minutes before theirs, you can expect an organised chain of attacks to drain you crystals.

I'm not saying whether it is wrong or right, but if you have a competitive fleet you should try your best to get into the chat or the very least be cautios of other payouts close to yours.