Fix Double NAT and VPN Access for Synology NAS

I'm seeking an expert to resolve double NAT issues and VPN access problems with my Synology NAS. Description of Problem: Here is a summary of my issue: 1) I have a DDNS from No-iP.com. The DDNS is Hidden.ddns.net 2) I have a Quantum 1000K ONT/Router device from my ISP... (Budget: $30 - $250 USD, Jobs: Cisco, Computer Security, Network Administration, Network Monitoring, Network Security, System Admin, VPN)