samalex - What you're experiencing is very normal. When I first began I felt like crap the first week, low energy, etc....lots of people do. You'll get past it, I promise.
It's also not unusual to feel full often. It was the carbs that made you hungry and now you're filling up on fat and protein.
Stick with it; you're doing fine and as you see the weight come off, you'll know it has been worth it!