Some of those "hunger pangs" may actually be "hungry for carb pangs." We've all experienced them in the first week, some even in the second week; that's probably why your coach said to see how things go the first week. 800 to 1000 calories a day is enough for you when your body is in ketosis, because it's getting the rest of the calories it needs from the excess body fat.
Make sure you're getting your 4 cups of veggies in a day, and eat all the lettuce you want.
Because your job requires you to move around a lot, your coach may suggest you have 4 IP packets a day instead of 3. Be careful with the things you are adding to your diet. You don't want to add calories or fat, even if it's 0-carb. Everything is specifically measured in this diet for optimal weight loss.
Finally, there is also an alternative Phase 1, which some have to go on before starting the actual phase 1. You may want to talk to your coach about this.
It's great that you're still losing weight! I'm sure that next week, you will start feeling better, if not more energetic.