This is terrible news, I am sorry for your loss.

Any ecommerce platform built on bitcoin/lightning is an incredibly risky venture. A tiny vulnerability somewhere could lead to a total loss of funds if things are not done carefully.

It sounds like the LNBank plugin (and perhaps all plugins) had no restrictions on withdraws, and so the attacks used it to drain your account.

Introducing plugins has been a growing trend with a number of platforms, and it compounds the risk of losing funds even further.

I wish you good luck with everything, and I hope that you will bounce back from this stronger than before.