I mean my BTC address. We all know that BTC transactions are public viewable, so i don't want the buyer to see all transactions i made before with other people.
No because you are using a 3rd party wallet (localbitcoins) to make the transaction.
Basically you deposit BTC into your LBC wallet and those BTC are then forwarded to a cold storage address where LBC holds all their BTC. When you sell to someone and they withdraw, the BTC comes out of that wallet and its impossible to find out which deposit BTC was used.
If you sold your BTC to someone using wallets like Blockchain.info, Electrum, Copay, Bitcoin Core, then yes he would know exactly what your public balance is on that BTC address.