I got consistent when I got a 5 year journal. Each page is one day, divided into five sections. Seeing that I would be revisiting it next year really helped motivate me, and reading previous years entries helps even more. Now I have several journals, and for the other ones, I either write in it when I do my 5 year, or I keep it open and jot in it all the time. The trick often is to just write something in it, and then its easier to keep going.
Also think about why you are journaling. Self reflection? Set an alarm. Memories? Read back in your old entries. Planning? Make it front and center so you look at it right away.
I don’t have the privacy concerns, so this other bit might not help as much, but I also use stuff thats pleasant to use. It does’t have to be luxury, but try going up a step. For paper, skip moleskin and look for a rhodia, leuchterm, or midori notebook. For pens, try a fountain pen like a platinum preppy, pilot kakuno, ot lamy safari. If you prefer ballpoint, skip the cheap ones ans get a Uni Signo gel pen or Pentel Energel gel pen. Having nicer stuff can really help motivate cause its nice to use.
Replace “do not exist” with “should not exist” and you are right on