I think i pulled a muscle in my lower throat/Neck?

Its hard to hold my head up, And its difficult to breathe unless i look up. If i turn my head sideways you can see "muscles" or somthing stick out that go down a ways. And i noticed that in between those muscles(above center of your chest where it meets your neck) it is almost like a whole, but its not a whole. its just indented, and that whole area is painfull to touch. What happend? What could of happend?