Hello.. what's your occupation?If you having desk job than first thing you have to take care of your posture during working hrs.
May be you having severe spasm in trapezius muscles assessment required some time bcs of spasm also will get headache.So my advice is meet physiotherapist and take pain relief treatment like IFT & ULTRASOUND for 7 days..than learn exercise to strengthen the muscles.
Next Steps
visit physiotherapist.
Health Tips
Avoid working on system with neck banding follow ergonomics.every 1hrly get up from the chair n move around and do some neck warm up exercise.avoid lifting heavy weight and apply pain relief gel and do hot formation fr 15 mins 2 times a day.