I do not trust anything that asks your private keys. Hackers even hack Ledger Nano, how can you think that MetaMask is safe?
My etherium wallet is hacked a month ago. I think it is hacked via Etherdelta or Metamask. I do not trust any of these sites. I suggest you the same, I would uninstall metamask right now. Sending anyone private key is insane
You probably got phished or you have some malwares,i have been using metamask for years without losing any penny from them.I trust metamask and mew,metamask is just an extesion recommended by myetherwallet,it is just a tool to protect your privatekeys from using etherdelta,it doesnt require your keys before using it.Do you really know how metamask works?