Routing Errorが解決できません

Routing Error uninitialized constant RelationshipsController　が解決できません。
友達一覧からフォロー、アンフォローのボタンを押した時にエラーが発生します。一通りネットにあるエラーを漁りましたが、できなかったので投稿させていただきます。宜しくお願いします。
accounts_controller.rb

class AccountsController < ApplicationController
    
    before_action :authenticate_account!
    
    
   def index
      @accounts = Account.all
   end
   
   def show
      @account = Account.find_by(id: params[:id])
   end
   
   
   
   def following
    
    @account  = Account.find(params[:id])
    render 'show_follow'
   end

   def followers
    @account  = Account.find(params[:id])
    render 'show_follow'
   end
  
end

routes.rb

Rails.application.routes.draw do
  
 
  devise_for :accounts
  get 'static_pages/home'
  # For details on the DSL available within this file, see https://guides.rubyonrails.org/routing.html
  
  root "static_pages#home"
  get "/home" => "static_pages#home"
  get "/howto" => "static_pages#howto"
  get "/accounts/sign_up" => "devise/registrations#new"
  get "/accounts/index" => "accounts#index"
  get "/accounts/:id", to: "accounts#show", as: "profile"
 
  resources :accounts do
    member do
      get :following, :followers
    end
  end
  resources :relationships,       only: [:create, :destroy]
  
  
end

show.html.erb

<h1><%= @account.id %></h1>
<h1><%= @account.username %></h1>
<h1><%= @account.email %></h1>

    
    


<% @account ||= current_account %>
<div class="stats">
  <a href="<%= following_account_path(@account) %>">
    <strong id="following" class="stat">
      <%= @account.following.count %>
    </strong>
    following
  </a>
  <a href="<%= followers_account_path(@account) %>">
    <strong id="followers" class="stat">
      <%= @account.followers.count %>
    </strong>
    followers
  </a>
</div>

<%= render 'accounts/follow_form' %>

_follow.html.erb

<%= form_for(current_account.active_relationships.build) do |f| %>
  <div><%= hidden_field_tag :followed_id, @account.id %></div>
  <%= f.submit "Follow", class: "btn btn-primary" %>
<% end %>

_follow_form.html.erb

<% unless current_account?(@account) %>
  <div id="follow_form">
  <% if current_account.following?(@account) %>
    <%= render 'unfollow' %>
  <% else %>
    <%= render 'follow' %>
  <% end %>
  </div>
<% end %>

account.rb

class Account < ApplicationRecord
  # Include default devise modules. Others available are:
  # :confirmable, :lockable, :timeoutable, :trackable and :omniauthable
  
  
  devise :database_authenticatable, :registerable,
         :recoverable, :rememberable, :validatable
  has_many :active_relationships,
          class_name:  "Relationship",
          foreign_key: "follower_id",
          dependent:   :destroy
  has_many :passive_relationships,
          class_name:  "Relationship",
          foreign_key: "followed_id",
          dependent:   :destroy
                                   
  has_many :following, through: :active_relationships, source: :followed
  has_many :followers, through: :passive_relationships, source: :follower
  
  
  
  # ユーザーをフォローする
  def follow(other_account)
    following << other_account
  end

  # ユーザーをフォロー解除する
  def unfollow(other_account)
    active_relationships.find_by(followed_id: other_account.id).destroy
  end

  # 現在のユーザーがフォローしてたらtrueを返す
  def following?(other_account)
    following.include?(other_account)
  end
end

accounts_helper.rb

module AccountsHelper
    
    def current_account?(account)
        account == current_account
    end
  
end

_unfollow.html.erb

<%= form_for(current_account.active_relationships.find_by(followed_id: @account.id),
             html: { method: :delete }) do |f| %>
  <%= f.submit "Unfollow", class: "btn" %>
<% end %>

relationship.rb

class Relationship < ApplicationRecord
    validates :follower_id, presence: true
    validates :followed_id, presence: true
    belongs_to :follower, class_name: "Account"
    belongs_to :followed, class_name: "Account"
end