Sorry to hear you are really struggling.The whole process of experimenting with ways to come out of depression can in itself be depressing.
Seeing you've tried just about everything inside the square, am wondering about any thoughts regarding things outside the square:
Let me start by saying that quantum physicists agree that we are energy. One might suggest we are energy in motion. Another way of putting energy in motion is 'Emotion'. How many forms of emotion do we hold? A few would involve physical emotion (matter or on a cellular level), mental emotion (thought) and natural emotion (the whole or holistic aspect of energy that happens both inside and outside of us).
The body is a truly amazing thing once you get to truly understand it in more of an emotional way. It can be almost humorous at times. A couple of examples. Perhaps someone you know is driving you crazy, day in and day out. After spending some weeks with them, you develop a pain you just can't seem to get rid of. Strangely enough, you would refer to it as a pain in the neck. Or maybe your shoulder area is so tight whilst you're experiencing terrible headaches. Maybe this all happens during a time where you feel like you are carrying the weight of the world on your shoulders and the stress of it all is making you feel like your head's about to explode.
Certain holistic therapies deal with not just specific ailments but a general over all approach to how energy is interacting. Certain therapies will deal with what lowers our energy, what makes it swing dramatically (due to internal and external factors), what raises it, what blocks the energy in motion (mentally and physically - taking us from dis-ease to disease) and the list goes on.
Whilst medicine deals with altering energy through medication and/or thought processes, the holistic approach simply tackles it from another angle. Finding someone highly reputable in the field of natural therapies is a must. Finding someone who'll explain the concepts used is significant.
I have seen natural therapies used on the greatest of doubters, with amazing positive results. Often, raising our energy or shifting it gently in natural ways can take us outside the square into a whole new world of self understanding.
By the way, I lived for about 15 years in my depression some time ago, experimenting with psychiatrists and meds. Very little of it worked for me. It can definitely become disheartening.