Do I need AWS Load balancer with nginx in AWS ECS?

I'm using Docker in AWS ECS. I have one EC2 machine with docker agent from AWS ECS, and the ECS task contains of 3 containers:

• nginx container
• application-nodejs container
• staticfiles-nodejs-application container.

I want to support very huge traffic. Do I need to setup AWSLoad Balancer? or my setting for nginx upstream is enough?

nginx conf example:

upstream appwww {                                                                                            
    server app-www:3000;                                                                                     
}                                                                                                             

server {                                                                                                      
    server_name  my.home.net;                                                                       

     location / {                                                                                             
        proxy_pass http://appwww;                                                                            
        proxy_http_version 1.1;                                                                               
        proxy_set_header Upgrade $http_upgrade;                                                               
        proxy_set_header Connection 'upgrade';                                                                
        proxy_set_header Host $host;                                                                          
        proxy_cache_bypass $http_upgrade;                                                                     
    }                                                                                                         

    listen 443 ssl http2; # managed by Certbot                                                                      
    ssl_certificate......; # managed by Certbot            
    ssl_certificate_key........ # managed by Certbot          
    include /.......# managed by Certbot                                     
    ssl_dhparam /.....pem; # managed by Certbot                                       

}                                                                                                             


server {                                                                                                      
    if ($host = my.host.net) {                                                                      
        return 301 https://$host$request_uri;                                                                 
    } # managed by Certbot                                                                                    


    listen       80;                                                                                          
    server_name  my.host.net;                                                                       
    return 404; # managed by Certbot                                                                          
}