What is stopping you from picking up your journal? Are you making an excuse for a lack of time? Let's observe where we can add a small amount of time to switch up your schedule enough to fit in a minuscule amount of journaling.
An amount of time so small that you can not make an excuse for not journaling. This is known as the kaizen practice in Japan. It's continuous, incremental improvement. It's taking it one step at a time instead of looking at the entire staircase and saying I can't do it.
Put your daily blinders on.
The most obvious time block is in the morning before the busyness of the day gets in the way. I like to read then write in the morning. I find this flow to be inspiring and enjoyable. Not a long time, but a 15 minute chunk of each is enough to feel like I've made some kind of progress on my journaling goals.
It's really important that you start so small you can not make an excuse. We are building momentum with this practice. Do it for at least a few weeks or longer! Seriously, do it until it's part of your routine.
By this point you'll be well into feeling the benefit of the daily practice. You'll begin to get into the flow state much more easily. That state of being where things become effortless. Of course, this is not to say it will be easy to sit down but once you overcome the action of putting your body in place, your mind will remember what it is supposed to be doing when you sit in your chair.
I recently heard an episode of the Tim Ferris Show with guest Jerry Seinfeld where he said you have to "treat your brain like a toddler". For me this means disciplining my brain from becoming distracted in the morning just long enough to read and write.
As artists and writers, this toddler brain is what leads us to explore and be creative but it is also our kryptonite when it comes to staying focused. Do you want to look back on your journal full of insights or have regrets for not taking the time to document them?
I think that you will thank yourself later for having the discipline to do the work.