Auggie, the EXACT SAME THING happened to me! He even snuck into my parents' basement to read older journals once he was done with the recent ones! Very sick relationship. I didn't write in a journal for 18 years after that.
Like you I now have someone I trust. Just wanted to share that I write every day in a journal now, and that has helped my recovery probably more than anything else. Go ahead! It's such a relief.