I have sever depression/anxiety. It seems the only medications that work are ones that increase endorphins. Do I maybe have an endorphin deficiency?

Not good treatment. Your first stop should be a medical exam ; workup to rule out medical conditions that may be contributing to your symptoms. Next, you should know that medication alone is not optimal treatment for anxiety or depression. For most depressed patients, the effects of antidepressant medication are indistinguishable from placebo. Proper treatment is *psychotherapy* (or therapy + meds), not meds alone.