You have a crick in your neck. Take ibuprofen and make sure you position your head in the correct anatomic position at night. You could make a small roll of towels and place this behind your neck so the back of your head is on the mattress ad your neck is supported, for example.
I will send you a link of some exercises that have been used for neck pain since WWII at least. They work.
Then just get plenty of sleep and give it time.
Thank you for your answers.
My pain is now gone and I am good.
Thank you once again!!!!