Chest bone crackling?

Hi people. i've read your infos about this subject and that encouraged me to join the forum. The thing is i am experiencing the same problem as you guys, and i think my case is a lot worst than what you feel. Mine is every time i hold down my head for like 2 minutes without moving, my chest will lock up. and when i try to straight my back i feel really painful on my upper part of my chest. when i stretch correctly i feel eased but if not, i feel like h'm dying because i need to crack it to unlock it. it gives me hard time especially in the morning when i get up, i feel weak sometimes. i can't even push my hands against each other when it locks. anyone can help me about it please..