You can try something like Obsidian out. It just saves your entries into Markdown files, so you'll always have a text version of them, and it will automatically

You can try something like Obsidian out. It just saves your entries into Markdown files, so you'll always have a text version of them, and it will automatically link together any tags you include within the document, so you can tag the concepts or subjects in your journals and then you can access them again via those links. It's kind of like a wiki, except markdown based, and in a cross-platform application. It's free as long as you don't want to use their cloud services, also.