Leafy, I know what you mean by 'feels like I'm gonna die'...when I take a hit sometimes, esp. on a really big rip, I know about a second after I stop that I took too much. The following happens:

1. Burning in back of throat, from immense harshness of smoke.
2. 'Chest caving in' sensation, as I breathe out. Throat-burning increases as smoke passes affected area.
3. About 3 seconds of calm, as my lungs are emptied.
4. Coughing fit, easily enough to cause vomiting IF it is not controlled.
5. I finish the bowl, as soon as I finish coughing long enough to toke again.

The best advice I have for you comes straight from my grandmother...make little coughs, instead of big, stomach-churning ones. Its kinda hard to explain, but instead of full-out coughing, try making small, throat-clearing microcoughs. Also drink some cool water, it helps to soothe your spasming throat muscles.

Btw, if you're taking rips this big, you should be smoking parachutes...they make you cough like this every damn time until you get used to it. Message me if you want a decent blueprint for making one.