Sounds like you need to write an app to do this. It seems you want to aggregate data from multiple sources, keep secret, then send.

I’m tech inclined, but not a developer, lots of low/no code solutions should let you get pretty close fairly easily.

I’ll bet you could use a jobs site to “rent a developer” and it wouldn’t be too expensive.

Or find a 3rd party to collect and schedule the email.

I think my email service does something like this, though I don’t use it.

https://proton.me/support/schedule-email-send

I settled on recipe keeper. It supports many platforms. It’s a one time purchase (per platform) and it has the ability to import from websites.

There’s also the xbrowsersync extension if you just want to save and sync bookmarks.

I may be a lost lemming though based on the community…