feel like im dying

Hi guys I'm hoping to get a bit of advice here I will start by giving everyone a bit of a background on myself.
I'm 23, 5'5 and 14.8 stone and I'm a smoker. Which is a big change because three years ago well obviously I was 20, 9.8 stone and 6'6(that part may have been a lie ) and I was healthy. But when holly came along I got lazy and stopped doing anything to do with exersizing. Anyway everyday now I wake up in really bad pain everywhere it's never ending on top of that I'm getting pretty down about it. Before anyone says it I have been to the doctor and been told there's nothing wrong. I guess what I want to know is has anyone ever experienced something like this, especially those who may be on the husky side like myself? And if so how did you go about helping it ease off ?. And any other advice is welcomed .
Thanks on advance.