Fixing Double NAT'd, reverse proxy, domain names

Looking for any possible ideas and solutions!

My ISP double NAT'd me, and finally (after 2 years) setup a port forward for me. So I setup a reverse proxy on my local network, then looked at the sub domain to redirect to different docker containers (services) internally etc...
However, its very annoying having to type the port in the FQDN (ex: https://sub.domain.com:23485/ It is annoying and ugly for me and my users.

These are the 3 possible "solutions" I have came up with so far... not even sure if they would work... Sadly it looks like Domain records (ex: cname, a etc...) are not able to redirect requests to an ip:port, only to other domain names or to a specific IP. So these are some alternative solutions I'm pondering on...

1. Setup a T2 Nano in AWS then setup a reverse proxy (or application level load balancer?) there to redirect to my public ip : port automatically.
2. Setup a VPN or tunnel? to basically anywhere... (A T2 nano, a friend/relatives house, or pay for a VPN service/box etc...)
3. Maybe a simple AWS Lambda function that can run and redirect the request? Not sure if S3 would be able to do it, but maybe???

Any insight on what will or will not work, or other solutions not listed would be greatly appreciated!