Sounds like one of the tools you have installed might have changed the /etc/resolv.conf file. You can just reboot your VPS to reset content this file back to its original state. If you don't what to reboot something like following should help:
echo "nameserver 127.0.0.1" > /etc/resolv.conf
echo "nameserver 22.214.171.124" >> /etc/resolv.conf
echo "nameserver 126.96.36.199" >> /etc/resolv.conf
here is what or at least what I think is correct way of doing this... I have tested this on another VPS the gui works but the internet connect, outbound does not aka can't ping domain names only ip addresses.
sudo yum groupinstall Desktop
sudo yum install tigervnc-server
sudo yum install xorg-x11-fonts-Type1
exec gnome-session &
after everything is working I can still ping domain names, yum updates etc. Reboot there goes the internet connection.
Is there a better way to load the gui? I tried previous solution and nothing and still no internet connection.