Why did my dog bite my nose off after i told my family that i could smell again? ? (it really hurts)

I don't know, is your dog okay?

Maybe your dog senses that you can smell again and wanted to see for himself :O

Otherwise how did you lose your sense of smell?

If your dog is okay, then give he/she food because maybe they think it is food. Or the other option to to pay more attention because dogs might do that for more attention (play with them more)