How To Treat Pain And Stiffness In Neck?

I have pain in my neck i think it s a stiff neck, i first felt it two days ago when i woke up but its not that bad another problem is i have problem swallowing even my own saliva i feel like my muscle in my neck is force to open the pain is coming from the affected area of the stiff neck first only at the left side of my neck is aching when i swallow but now both sides are aching..