Thanks to everyone for your support, tips, and advice.
It is more than just this wedding - it is the fact that I can't live the lifestyle I was leading up until the end of 2009, which was a 40+ years lifestyle of doing what I wanted, eating and drinking what I wanted and not worrying about the consequences.
In early 2010 I started suffering from severe anxiety; upon going to the doctor I discovered my blood pressure was dangerously high, which increased my anxiety.
Over the last 3 years I have been on medications and trying to clean up my act but kicking alcohol was what I really needed to fix my mental and physical issues.
I now feel like I just exist and life isn't any fun; I can't indulge in any "bad behavior" in fear that it will hurt me so even if I did drink I wouldn't really enjoy it.
I am such a mess.