In this case, the lovely Firebird is correct.
"The word shaman comes from the Evenki and related Tungusic languages such as Manchu, where it also appears as samaan or s’aman. European invaders and travellers picked it up in the late 1600s. Later, Russian ethnographers and European anthropologists used the word beyond its original ethnic context"
From:
http://www.sourcememory.net/womanshaman/samaan.html
(Most sources say this, and this is the most succinct answer)
The article goes on to say that are also similar words in a Sanskrit and Chinese, though linguists don't think the etymology of the word is derived from these groups because of research into tones.
The word 'Shaman' in its current context was quickly applied by anthropologists to describe the magical practices of original people's healers. We have the anthropologists and popular museum culture of the 18th and 19th century to thank for the fact that we use this one word in a general sense-to describe the gifted healers of indigenous societies around the world. These indigenous groups would have people in their communities who practiced magic. Many of these practices the world over have similar devices for delving into the sacred, and this is what current 'nouveau shamanism' is based on.
Traditionally practitioners were important people in the contexts of their communities, even though their status and power could sometimes be equated with fear and a bit of distancing. The ska'age was a powerful person who was called on in times of sickness to diagnose and heal. People are people and as such would practice good or bad work depending on their will. Where I am from, the shaman would not live in the centre of town, and consequently upon death he or she would probably be buried a distance form the village and others. Respect of their power carried on into death.
Of course indigenous peoples the world over had their own words, in their own languages meaning "shaman". Ska'ages or sa'arawas are the words for medicine person where I was born.
Technically, a shaman's practice would be dictated by the culture in which they lived...magic, the land, animal and plant energy, and belief would intertwine from time immemorial and that would dictate practice. The ska'age would have animal allies linked to shamanism in that land....certain animals are the shamans domain, and within that certain animals and spirits would work specifically with that ska'age.
I really don't know much of anything of of druids or shamans really, but I wanted to say hello. I'm very much where you are in trying to get back to my path. I deal with anxiety and depression as well and it kind of led me off my path. But in grief I've realized how much I need it. 
