If this happened to me then I'd change ISP. NAT on your home Internet? What is this, the US?
I thought if you were in Europe you'd pretty much always be able to get public IPv4, IPv6, and IPv6-PD. I know I can.
As you might guess, the ISPs that are forced to use CGNAT due to the lack of IPv4 addresses, are also the ones who tend to be the first on IPv6, for obvious reasons.
I know of a big ISP, a relative latecomer, infamous due to its CGNAT issues, who last summer boasted reaching 99% IPv6 coverage.
(And at the same time, for some reason they had to be forced by the government threats, that otherwise they would not be allowed to use 5G, to add opt-in IPv6 on cellular, which they did at the last moment last month...)
If any of those points do not apply to your ISP, that's not because of CGNAT, it's just a shit company. I've used four different ISPs in the past four years and getting rid of CGNAT has not been a problem once. IIRC only one of them used public addresses by default, two offered free dynamic IPs upon request and my current ISP offers paid static IPs for $3.
Tons of my friends and family have had CGNAT and never known. It's just not a big deal for most content consumers.