Windows Server 2016 No Internet Access after AD, DNS and DHCP setup

I have a Windows Server 2016 on which is setup as a Domain Controller. I have AD, DNS and DHCP setup on the same server. The DNS server address is localhost and DNS forward has been setup for the default gateway server locally.

I cannot get internet access on my server using localhost as mt DNS address. But if I use default gateway as DNS server internet access works so I know there is something wrong in my DNS server setup and forwarding.

Please help?