I am unable to sleep with neck stiffness. Kindly help me.

I'm at my wits end, the doctors in my area don't care anymore. It's here some pain meds, have a great day. But, I'm getting so much worse. Long story short my neck locks up completely. If I keep my neck in a position more than a minute, it gets so tense, and painful. The only way to relieve it is to crick my neck to the side, and you can hear a physical pop. No one seems to know what is wrong, but they don't dig very far. I can't sleep anymore because driving, and sleeping, are when it happens the most. I have spinal stenosis, degenerative disc disease, and herniated discs in my neck, but no one seems to have any result as to what causes the neck pain. It's like stiff and cracky. I've tried every medication like muscle relaxers and nerve pain meds etc. I've done physical therapy for it nothing is helping it's only getting worse. And it's not like you can help for neck stiffness, popping to relieve it. I just need to know what's wrong with me :-(