Is there something bothering you? Has something happened in your life recently which has been difficult for you? You mentioned pain; is that a physical pain or emotional? Stress and unresolved issues can be a cause for chronic depression. Please see a psychiatrist who will be able to treat your depression with medications and therapy.

Start by getting a hobby and making a close friend. Learn how to focus on priorities and note down big or small things that make you happy and focus on them.