Yes as Anna said medication might be needed so go to your doctor and have a talk about it to him, you shouldn't be feeling like that all the time. The first couple of months can be a drag sometimes because your getting over cravings, getting to know the new you and finding motivation to do things can be hard.
I've found it good to really get involved in something you really like. I am a huge music fan and spend alot of time listening to it, going to gigs, buying cd's etc. Just throw yourself into something.
In regards to food the opposite has happened to me. I weighed in at 110kg at my heaviest because I was drinking too much beer and eating too much. I'm now around 103kg and I think if you feel hungry you should eat because it can trigger cravings and going back to alcohol sometimes. Maybe try something healthy (plenty of fruit and vegetables) won't put on too much weight.