Help renewing cert (and making it renew in the future)

So I already have certbot installed, I thought it was set up to auto renew, but my website now says it has an expired cert.

Ubuntu 16.04.2 / nginx / pm2 / node

I tried certbot renew and got this output:

Saving debug log to /var/log/letsencrypt/letsencrypt.log

-------------------------------------------------------------------------------
Processing /etc/letsencrypt/renewal/lospec.com.conf
-------------------------------------------------------------------------------
Cert is due for renewal, auto-renewing...
Renewing an existing certificate
Performing the following challenges:
tls-sni-01 challenge for lospec.com
Cleaning up challenges
Attempting to renew cert from /etc/letsencrypt/renewal/lospec.com.conf produced an unexpected error: Could not bind TCP port 443 because it is already in use by another process on this system (such as a web server). Please stop the program in question and then try again.. Skipping.

All renewal attempts failed. The following certs could not be renewed:
  /etc/letsencrypt/live/lospec.com/fullchain.pem (failure)
1 renew failure(s), 0 parse failure(s)

I’m afraid to do anything more as I don’t want to screw up my server. I’d like for the cert to just auto renew.