I had the exact same problem forgetting appointments and missing big things on my to-do list. Digital just doesn’t work for me. So, I started using a bullet journal. It’s a bit more work because you have to design your pages and set up each week, but I like the flexibility of it. I just keep it simple but I have goal pages, “to-do” pages, notes pages about various topics, as well as my weekly and monthly pages. Mine was about $7 at Hobby Lobby or someplace. Great read!