Re: A couple of questions
What type of coals are you using on your hookah? The headache could be caused by too much carbon dioxide. If you are using quicklites switch to Naturals when you can. The harshness most of the time atleast with regular tobacco, is when you are burning the tobacco. Which is caused by too much heat. The herbal stuff may be a lot more heat sensative.
(*Disclaimer* These are my opinions and mine alone. It does not reflect the opinions of others and is based on my personal smoking enjoyment and experience)