Hi, I've been a smoker for nearly 4 years now, I used to be able to smoke fine, but about 5 months ago I started having the urge to vomit half way through smoking my cig. I do have the intention of stopping smoking at one point or another, but my mind doesn't feel ready to quit at this exact moment in time due to circumstances that I need to bare through. If I have a sip of a drink after I feel the urge to vomit then I can carry on smoking the rest of my cig in peace, but it can be a minor inconvenience. What could be causing this?