rails seedデータ流し込みエラー対策

rails db:seedでエラー発生

エラー文
rake aborted!
ActiveRecord::RecordInvalid: Validation failed: Email has already been taken

$ rake db:drop
$ rake db:create
$ rake db:schema:load
$ rake db:seed

gitで前まで戻る、

rails db:migrate
rails db:migrate:reset
rails db:migrate
rails db:seed　でエラー発生