502 Bad Gateway nginx/1.10.3 (Ubuntu) after server reboot

Took over the website for a company. After resetting the server password and rebooting the server, the site is now giving a “502 Bad Gateway nginx/1.10.3 (Ubuntu)” error.

Checked the nginx error logs and getting several errors similar to this (replaced client IP and website name for privacy):

2018/09/02 19:09:09 [error] 4531#4531: *1 connect() failed (111: Connection refused) while connecting to upstream, client: 0.0.0.0, server: mywebsite.com, request: "GET /favicon.ico HTTP/1.1", upstream: "http://127.0.0.1:3035/favicon.ico", host: "mywebsite.com", referrer: "https://mywebsite.com/"

Checked /etc/nginx/sites-available/default and this is the config (again, site has been changed for privacy):

server { #80 IS THE USUAL PORT TO USE HERE

     server_name mywebsite.com www.mywebsite.com; #PUT YOU$

     location / {
          proxy_pass http://127.0.0.1:3035; #PUT YOUR SERVER PORT HERE
          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; # managed by Certbot
     ssl_certificate /etc/letsencrypt/live/mywebsite.com/fullchain.pe$
     ssl_certificate_key /etc/letsencrypt/live/mywebsite.com/privkey.$
     include /etc/letsencrypt/options-ssl-nginx.conf; # managed by certbot
     ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by certbot


}
server {
     if ($host = www.mywebsite.com) {
          return 301 https://$host$request_url;
     } # managed by Certbot


     if ($host = mywebsite.com) {
          return 301 https://$host$request_url;
     } # managed by Certbot


     listen 80;

     server_name mywebsite.com www.mywebsite.com;
     return 404: # managed by Certbot




}

Tried several suggestions found through community and can’t seem to get this to work. Any help would be greatly appreciated.