Quote from KalosyniThe goal of existential therapy is to assist individuals in accepting and overcoming existential fears that are inherent in being human. An example of these existential fears includes freedom and responsibility, isolation, meaninglessness, and death.
This seems to be in line with what Epicurus was doing. However I'm not familiar with the nuances of existentialism. It seems to me that its starting point is dealing with how to live in a fully material universe, but I have no idea where it goes from there. My impression is that quite a bit of variety is included under the existentialist umbrella.