Not trying to disagree with what some others have said, but sounds an awful lot like anxiety to me. Sounds like you're on the verge of a panic attack, which is many times worse too. I went through the exact same symptoms that you're experiencing. Are there any new stresses in your life? (this will not usually be as easily noticeable as it seems, everyone thinks they're doing fine...). This is exactly why I can't smoke much anymore. Either get you're head straightened out with whatever may be subconsciously causing anxiety, or keep some benzos on hand to quickly kill the feeling.
I try not to take them all the time, I just try to smoke less at a time, a few hits get me good now. I do keep them around though because if you have a full on panic attack, you will think that you're dying, it really feels that horrible. Those muscle tremmors will get stupid strong, those painful feelings could reach throughout your body, you will feel unable to breathe and you chest will hurt. You could develop shock symptoms too. I have seen others go through this as well, everyone thinks they're having a heart attack, but it's suprising how quickly benzos will put a stop to it.
I used to be a daily (all day) smoker but now i rarely smoke more than once or twice a week, it sucks. OR, you could just take a break like everyone else said, which isn't a horrible idea (but who wants to do that?)
Good luck man, hope you can get over this
