I'd make killing off the parasites a top priority. Killing off the parasites will strenghten the immune system long term because the amonia the parasites emit cause the immune system to work harder to eliminate it.
I don't use mushrooms - they are a fungus, and we don't want fungus in our body. I really don't know much about mushrooms, but it seems to me that there are a lot of other stuff to do the same job that are not a fungus.