Hi Skinny,
Are you actually vomiting? If so I would get that checked out. The first few days can be rough. You will go through sugar and carb withdrawals, and your body will be adjusting to LT. This will leave you feeling headachey, tired, light headed and generally feeling a bit poo. After a few days ketosis kicks in and everything changes. The hunger pangs will disappear and if you're lucky you will be bursting with energy. The initial first few days will become a distant memory.
Please go to your pharmacy and get checked. Tell them exactly how you feel.