I wake up every morning with a dry and sore throat and often choke on water. is this a sign of throat cancer.

Not really, but: It doesn't sound like any fun. Why don't you have your doctor take a look and go over any medications you are using. Stop smoking if you do so.

Not my first thought: You may be a mouth-breather at night. Perhaps you have nasal congestion from seasonal allergies. That would be my first thing to address. Maintain your recommended medications for this if it applies. Perhaps you should visit with an allergist or an ENT or your primary care physician to see if you need assistance with nasal congestion. As far as the choking on water, I am not as familiar with that.