Sigrid GF, you're close to being up the proverbial sh-- crick without a paddle as far as your protein sources. This is the first time I heard that soy affected thyroid, so I really can't comment further on that.

some suggestions:
Organic chicken -- no hormones.
Farm-raised fish -- should be no mercury
For the fish and chicken, go to a health food grocery.

and everyone's favorite:
beans and rice

Can you have eggs?