No your bitcoin's aren't blocked, you just can't sell it directly because apparently they're experiencing some problem. Your bitcoins should still be transferable to other wallets.
There are a lot of exchanges/platforms actually where you can buy and sell bitcoin such as these
We also have our
Currency Exchange section here. You can make a thread there stating what you need e.g.
Buy bitcoins through N . If you're not dealing with a trusted member, you should ask for an escrow as scammers are everywhere.
First of all, u dont have wallet on blockchain its impossible, u have wallet on website called blockchain.info.
Never keep ur funds on exchange/online wallet. Its worst way possible.
This is true. You should look for a better wallet particularly if you're into HODLING.
Hardware wallets are the best choice in this and it only costs less than $100. If you're not into spending there is Electrum (Lightweight Desktop wallet), Bitcoin Core (Full Node) or Mycelium (Android Wallet)