Ruby on Rails: How to store data in two tables following the creation of a record in one?

I have two database tables Users and Accounts, when a new user is created their primary email address that they will use to login is stored in the Users table. What I want to do is also store a copy of their primary email address in the Accounts table, as this table will be used to store the email addresses of that user.

I have tried the following in my users_controller:

class UsersController < ApplicationController

  def index
    @users = User.all
  end

  def show
    @user = User.find(params[:id])
  end

  def new
    @user = User.new
  end

  def edit
    @user = User.find(params[:id])
  end

  def create
    @user = User.new(user_params)
    if @user.save       
        session[:user_id] = @user.id
        @account = Account.new(email: params[:primaryemailaddress], user_id: session[:user_id])
        redirect_to @user
    else
        render 'new'
    end
  end

  def update
    @user = User.find(params[:id])

    if @user.update(user_params)
        redirect_to @user
    else
        render 'edit'
    end
  end

  def destroy
    @user = User.find(params[:id])
    @user.destroy
    redirect_to users_path
  end

  private

  def user_params
    params.require(:user).permit(:title, :firstname, :surname, :housenumber, :street, :city, :postcode, :organisation, :primaryemailaddress, :password)
  end  
end

And the following in my User model:

class User < ActiveRecord::Base
    has_many :accounts
    accepts_nested_attributes_for :accounts
    validates :primaryemailaddress, presence: true
    has_secure_password
end

So, as you can see in the create method in the users_controller, I am trying to create a new record in the Accounts table using the primary email address the user has entered on the registration form.

Can someone please tell me where I am going wrong?