I mean my rss entries are saved as opml file*

On windows I use fluent rss reader. Pretty slick app. It also has a paid android app ( which I haven't used, but recommend because I'm sure it would be great, since its the same developer as I understand). These files are saved as an opml files, which I have uploaded to a github ( private ) repository, so I can keep using the same thing in multiple devices. That's it.

You're never alone ... specially not on nostr nor on internet!