Am I screwed? Transferred USDT from Polinex to USD dollars in Coinbase and now it's gone
You do not have access to your Private keys on coinbase, as it is considered a custodial wallet, which means only they have access to it. I highly doubt they would give you these private keys as its not standard practice. You only option is to email support. I doubt they would care. Another option is to ask someone inside coinbase to help you, but you'll need connections to do that I imagine.