The back of my head the bottom part hurts real bad i haven't been sleeping good & been under a lot of stress?

Sleep: Pain in the back of the head needs to be evaluated by a physician, hopefully its only stress related but brain, muscle, skeletal causes need to be ruled out.

The stress & poor : Sleep could be contributing to discomfort. You may have tension in your neck & head muscles. One thing that you can do to self-calm or reduce anxiety is deep breathing. Breath in slowly & deeply through nostrils. Fill you lungs with air & hold for a five count. Slowly exhale through open mouth. Don't focus on problems. Think only about your breathing. Repeat x 12 or until you are calmer. I >.