I used to have this exact thing. It sometimes even smelled like broccoli too.....(?) Unrelated to it, I did an intestinal parasite cleanse and the smell went away. While cleansing, I read alot about parasites, and cleansing, and found that parasites byproducts are ammonia. It took me months to make the connection between the two. This is probably really gross to read, or think about, but I feel a million times better and had no real reason to think I needed one in the first place (havent left the country, dont have pets, etc) but now after all Ive read and learned I do believe that waay more people have them than realize. Hope this helps.