So I thought about buying Bitcoins and sending them to an external address, but I can't make purchases and I can't send cryptocurrencies. In short, everything is blocked!
Maybe they disabled PayPal withdrawal for everyone as they didn't mention that only you have been disabled. Another question is why you can't buy buy and send them to other wallets. Maybe only you are restricted for withdrawal. That's why I don't suggest to store funds in any custodial wallets. We should keep as much as we can afford to lose or should withdraw immediately after closing trading positions.
And don't worry about this because sometimes if custodial wallets detect suspicious activities then they disabled withdrawal temporarily. And hope support team will resolve your issu asap as Coinbase is a well-known, trusted and reputated exchange so far.