Force WWW behind an AWS EC2 Load Balancer

I've come up with a small issue, we're using a load balancer for a new project, but we cannot force the www. without having a redirect loop between requests.

We're currently using NGINX, and the snippet to redirect is the following:

LOAD BALANCER NGINX CONFIG

# FORGE CONFIG (DOT NOT REMOVE!)
include forge-conf/mywebsite.com/before/*;

# FORGE CONFIG (DOT NOT REMOVE!)
include upstreams/mywebsite.com;

server {
    listen 443 ssl;
    listen [::]:443 ssl;
    server_name .mywebsite.com;
    
    if ($host !~* ^www\.){
        rewrite ^(.*)$ https://www.mywebsite.com$1;
    }

    # FORGE SSL (DO NOT REMOVE!)
    ssl_certificate /etc/nginx/ssl/mywebsite.com/225451/server.crt;
    ssl_certificate_key /etc/nginx/ssl/mywebsite.com/225451/server.key;

    ssl_protocols TLSv1 TLSv1.1 TLSv1.2;

    charset utf-8;

    access_log off;
    error_log  /var/log/nginx/mywebsite.com-error.log error;

    # FORGE CONFIG (DOT NOT REMOVE!)
    include forge-conf/mywebsite.com/server/*;

    location / {
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_set_header Host $http_host;
        proxy_set_header X-NginX-Proxy true;

        proxy_pass http://370308_app/;
        proxy_redirect off;

        # Handle Web Socket Connections
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
    }
}

# FORGE CONFIG (DOT NOT REMOVE!)
include forge-conf/mywebsite.com/after/*;

HTTP SERVER NGINX CONFIG

# FORGE CONFIG (DOT NOT REMOVE!)
include forge-conf/mywebsite.com/before/*;

server {
    listen 80;
    listen [::]:80;
    server_name .mywebsite.com;
    root /home/forge/mywebsite.com/public;
    
    if ($host !~* ^www\.){
        rewrite ^(.*)$ https://www.mywebsite.com$1;
    }

    # FORGE SSL (DO NOT REMOVE!)
    # ssl_certificate;
    # ssl_certificate_key;

    ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
    ssl_ciphers 'ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:kEDH+AESGCM:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-DSS-AES128-SHA256:DHE-RSA-AES256-SHA256:DHE-DSS-AES256-SHA:DHE-RSA-AES256-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:AES:CAMELLIA:DES-CBC3-SHA:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!MD5:!PSK:!aECDH:!EDH-DSS-DES-CBC3-SHA:!EDH-RSA-DES-CBC3-SHA:!KRB5-DES-CBC3-SHA';
    ssl_prefer_server_ciphers on;
    ssl_dhparam /etc/nginx/dhparams.pem;

    add_header X-Frame-Options "SAMEORIGIN";
    add_header X-XSS-Protection "1; mode=block";
    add_header X-Content-Type-Options "nosniff";

    index index.html index.htm index.php;

    charset utf-8;

    # FORGE CONFIG (DOT NOT REMOVE!)
    include forge-conf/mywebsite.com/server/*;

    location / {
        try_files $uri $uri/ /index.php?$query_string;
    }

    location = /favicon.ico { access_log off; log_not_found off; }
    location = /robots.txt  { access_log off; log_not_found off; }

    access_log off;
    error_log  /var/log/nginx/mywebsite.com-error.log error;

    error_page 404 /index.php;

    location ~ \.php$ {
        fastcgi_split_path_info ^(.+\.php)(/.+)$;
        fastcgi_pass unix:/var/run/php/php7.1-fpm.sock;
        fastcgi_index index.php;
        include fastcgi_params;
    }

    location ~ /\.(?!well-known).* {
        deny all;
    }
}

# FORGE CONFIG (DOT NOT REMOVE!)
include forge-conf/mywebsite.com/after/*;

Thing is, with this config I'm only getting redirect loops from the server.

Help please :D <3