There are a ton of meditations out there that can help center your mind and get it off of the booze, try looking one up and giving it a shot.
I used to always think meditation was a stupid practice, until I started practicing it. It has truly helped me become a better person.
In regards to the party, that is going to be a tough situation. My advice would be to not have the party; however, if you feel you must still have it always have a tonic and lime in your hand just to avoid having people push drinks on you.
Glad you are here, be strong and you will get through it.