My suggestion is that you should create a paper wallet or an offline wallet, and send all or most of your bitcoin there. You will need to take some extra time and effort to spend those bitcoin, and hopefully that helps you fight off the urge to gamble.
What is a paper or offline wallet?
In short, a paper wallet is a piece of paper containing your private key(s) and you have to store that paper in a secure place. Check https://en.bitcoin.it/wiki/Paper_wallet and http://www.coindesk.com/information/paper-wallet-tutorial/ for details.
To spend the bitcoin, you will need to scan the QR code first to import your private key to your computer/phone.
An offline wallet is a wallet that never connects to the internet. Check https://en.bitcoin.it/wiki/Cold_storage for some info.
Usually, a paper wallet or an offline wallet is used to provide an extra level of security as it is safe against hackers. But in this case, it may make it a bit harder for you to spend your bitcoin which hopefully could helps you fight off the urge to gamble.