did you make changes at an iptables firewall or another firewall? The "all services down" effect often comes from that. If so and you still have access to your server you can flush the iptables settings:
sudo iptables -F INPUT
sudo iptables -P INPUT ACCEPT
Do it only if you are sure that you want to reset your firewall config. ACCEPT everything is the default firewall config. You may wish to show the INPUT rules before by invoking:
sudo iptables -L INPUT
All those commands can as well be done with the chain OUTPUT instead of INPUT. Default is all Chains empty and all ACCEPT.
Greetings from Switzerland, Michael