lung cancer fatigue

Is this Lung/ Throat Cancer?
Im a male, 19. Smoking for about a year and two months on and off. Smoked about 15 packs in total in that time. I quit cold turkey 3 weeks ago because stiffness in my chest, by my sternum, when i tilted my head downward. And stiffness by the base of my neck when i tilt it backward. I wasn’t sure what that was. Also, since then I had three slight nosebleeds, shortness of breath and fatigue . Is this just symptoms of quitting or is it cancer…I cant find anything on the internet that would explain the stiffness though…any thoughts? I am going to stick with not smoking though.
I can’t tel you, I don’t think its cancer, go to your doctor, i know theres nothing on the internet, but i guarantee your doctor will know, i looked things up on the internet, nothing for me, but my doctor said other things, they know trust me! Good luck, eat healthy be healthy!
HOW TO CURE FATIGUE
