This sounds like you are triggering panic attacks when you smoke. Try smoking less weed and see if you feel okay with just a mild buzz, then go from there. I have anxiety, and occasionally weed will spark a panic attack for me. It's just like how you describe, feels like you're fucking dying. Try to remind yourself it is just a temporary feeling, go for a walk and remind yourself that you're not collapsing or having anything serious happen even though it feels that way, drink cold water, and take slow deep breathes. Talk to a friend or try to get distracted with a fun high activity. The feeling will pass. Some people can't smoke due to panic, but I have found weed helps my anxiety more often than not so I've just learned to adapt to the occasions that I do panic. In the end, if it happens every time and makes you miserable, there's no shame in not smoking.