That sounds terrible and I hope you are finding something that works for you!
Heavy metals are most likely what caused things to get out of hand, not necessarily the doxy. If you do have a parasite infestation then steroids would certainly have pushed you over the edge. They have found that treating horses with steroids when infected with strongyloids was too cruel to the animal! Steroids suppress the body so much that the parasites proliferate like crazy. At least that's my take on it, there's probably more scientific realities. Taking steroids should only be done in a life or death situation in my opinion.