Do you take salt flushes when you get the swollen throat feeling and anxiety? Does it calm the anxiousness, or are you still feeling wonky after two glasses of saltwater and having a good pee? ( recipie at https://www.curezone.org/blogs/fm.asp?i=2118222 )
Sulfur gives a sensation of calm and chill. It's my go-to when I have trouble sleeping (I use epsom salt, and less commonly, thiamine (vitamin B1), MSM (methylsulfurmethane) and biotin). If you're not taking a b-complex vitamin beside the selenium, you're probably way on the 'too much right now' side of the teeter-totter with selenium.