I hope it works out for you! If you're Linux based, I recommend jrnl. It's a lightweight terminal tool that handles logging and accessing your journal entries and has an encryption option built in. Through the config, you can use whatever text editor you want. I'm using vim because I hate myself!

As for the experience, it really takes some time to get used to. When I first started, I found myself "faking it" for lack of a better word. I wasn't actually writing what I was feeling, I was writing what I'd want someone else to read if they found it. After a while, that became less of the norm and I started treating it like a pen pal that I never heard back from. It lets me kind of put things into perspective and really dig into why I think I'm feeling what I'm feeling. Writing that you're mad won't make you not mad. Writing what made you mad, why you think it bothers you, etc. Won't really make you not mad. The latter helps you understand what's going on better and then you can work on regulating yourself from there