I can't seem to figure out what had happened to access some of my apps using Duck DNS, domain, swag, etc....need some advice!

I'll start off saying, I am NOT very knowledgeable about how everything really works. I mostly get by using how to's and such. That said, this had been working for a couple years and it stopped working at some point and I cant seem to figure out what is wrong and how to get it back going again.

I have Duck DNS set up and it points to my public IP, I also have a custom domain with subs like nextcloud.mycustomdomain.com and they have cnames that point to the Duck DNS url. If I go to DNS checker and type in nextcloud.mycustomdomain.com it shows the CNAME with the DuckDNS domain, and if I search the A record it shows my public IP address. So it seems like everything is pointing to my public IP correctly. But its not getting into the server. I also have SWAG setup and while it APPEARS to be set up right, there must be something set up wrong between SWAG and my home router since these are getting to my public IP then ending there but I cant remember how to set it up where the router to SWAG to let me through....I may need to reconfigure a port in the router or something but I'm not sure how to do that.

Can anyone give me any advice? I'd put up some screen shots or something but I'm not even sure what to screen shot, if you want to see something just let me know....or if someone can just point me in the right direction of what to check that would be good too, because I don't really want to display much publicly anyway.

Any direction you guys can give is GREATLY appreciated!