Hi Mark,
I have to say I really admire your determination in the face of such setbacks. You have my respect. Many would have thrown in the towel and walked away.
I use Horse Manure and my own Garden compost. I source my Horse Manure from racing stables as these have to be very careful about what chemicals the horses come into contact with either directly or indirectly and thankfully I have never encountered the problems you have faced.
I’m sure it will all come right for you in the end,
Don.