Nginx Vhost shows the default index page and not the one that defined

I recently installed nginx on debian 8.8 server. I have registered a domain name and now I want to create a virtual host to serve it. (In the future I might add more virtual hosts for other domains.)

The problem is that every time I enter http://[my domain] I get the default nginx welcome page rather the one I created under /var/www/[my domain]/public_html.

Bellow I post the commands I typed to create a new vhost:

sudo mkdir -p /var/www/[my domain]/public_html
sudo chown -R www-data:www-data /var/www/[my domain]/public_html
sudo chmod -R 755 /var/www
sudo nano /var/www/[my domain]/public_html/index.html
sudo nano /etc/nginx/sites-available/[my domain]
sudo ln -s /etc/nginx/sites-available/[my domain] /etc/nginx/sites-enabled/[my domain]
sudo rm /etc/nginx/sites-enabled/default
sudo service nginx restart

in the vhost file I added the bellow lines:

server {
    listen         80;
    listen         [::]:80;
    server_name    [my domain] www.[my domain];
}

server {
    listen         80;

    default_type text/plain;
    root   /var/www/[my domain]/public_html;
    index  index.html index.htm;

    location / {
        try_files $uri $uri/ =404;
    }
}

I checked the configurations with sudo nginx -t and no error reported.

I run ufw firewall with the following configurations (in case that someone wants them):

ssh                        ALLOW       Anywhere
Nginx HTTP                 ALLOW       Anywhere
shhh                       ALLOW       Anywhere (v6)
Nginx HTTP (v6)            ALLOW       Anywhere (v6)