Hi..
Straight neck has no connection with fibromyalgia..!
Ur straight neck is due to spasm in ur neck muscles which looks after your neck fexibility.. the C curveture of your neck is disturbed so there’s pain n stiffness..
Next Steps
Start with hot water formatation for 15mins, apply myolaxin ointment, perform all neck movements 5times each.. stretch them as much as u can,, no over stretching as it will agrevate ur pain,
Neck mobilization is important in ur case for that physiotherapy is mandatory.!
Most Important is to follow ur neck exercises daily lifetime.. if u stop ur exercises the pain has to be
ON/OFF..
Take proper care,,, stay healthy..!!