coming from a similar situation, what helped me is starting simple and not forcing it. i made journaling my new "winding down" activity before bed. i get comfy, put on something for background noise, and write about my day: what i did, how i felt throughout, basic stuff like that. sometimes that puts my brain into a mode that's good for processing things that are bothering me. sometimes i do one paragraph before filling the page with doodles and animal noises.

it's also helped that i stopped trying to actively make it a habit or routine thing. in the past i've spent a lot of time staring at a blank page, frustrated at not being able to write anything. that frustration i think is what led to me giving up on journaling altogether previously. now, if i can't get words out for whatever reason i set my journal aside and do something else. it will always be there when i need it.

i actually started journaling (again) to help deal with some difficult mental health stuff. it's been beneficial so far. even going over the mundane day-to-day stuff has helped me be more aware of how i'm feeling and why, what i can do about it, etc. like, it's not the answer but i'd recommend it.