For me cognitive behavioral therapy with a very good psychotherapist was fundamental. I will just say what my therapist told me at the end of the first meeting "If you want it to work it will work, but if your problems were created in years of mental distress they won't go away any faster, it will be a long way. Be prepared."

Almost 3yr later I still have some very random depressive toughs in my head and sometime two or three very bad hours, but now I can recognize them for what they are and that part of my mind lost any real control on my daily life. I can focus freely on my work, I can finally sleep like a normal person and my biorhythm is finally decent after years of total randomness caused by almost self-imposed insomnia.

Consider investing in it, it was probably the best decision of my whole life.