Hi Matty and welcome to Neurotalk
although I agree that alcohol can
seriously mess with one's mind, yet it also sounds like you might be dealing with more, and often it is a chemical imbalance that can cause these things. It may well be that you are attempting to self medicate with the alcohol which sadly, as you have learned, only masks the symptoms temporarily and then leaves you feeling worse
my son suffers with intense OCD and needs to take supplements that keep his serotonin levels elevated. Some people find medications help with this (my son had yuck side effects from those so chose the other treatments)
the crux of the matter is that if these thoughts, moods and panic attacks are at the stage where you are worried, you really should consider a medical check up.
also thinking you may want to post on our alcohol/addictions forum
http://neurotalk.psychcentral.com/forum31.html
hope you get answers and help