As other have said, I can't give much advice as I don't fully understand your condition and would hate to give you the wrong advice (so take everything I say with a grain of salt

). In regards to the fish oil, these tablets give you all the same benefits as fish oil tablets. They are made using concentrated amounts of algae, which fish eat to get their nutrients from. So they're basically just cutting out the fish and getting it straight from the source.
http://www.opti3omega.com/opti3.html
Maybe try showing them to your doctor and see what they think?
Also, I would strongly suggest getting a second, third or even fourth opinion on the matter! Different people will give you different advice, and it never hurts to get another opinion from someone else.
If it does come down that you need to eat animal protein, then buying free range will be an obvious choice. Also remember you can always help animals in other ways too

Like buying products not tested on animals, making donations, donating your time to shelters etc.