Is it enough to journal or do I need to talk to the person?

Good question, Ronnie! First of all, please acknowledge to yourself that you're already taking a big step just being here, being open to this work, and doing the work. Don't downplay this! Give yourself credit! You've already got your "big girl" pants on

And yes, it's a good question, but there is no one answer, because everyone's situation is different. For me, the best technique was the unsent letter, because the things I wanted to say to the individuals were things that my brain was repressing as being too dangerously negative to be acceptable. But writing a letter specifically TO the person was very freeing, even though I knew they would never read it.

One was to my mother, which I never sent, but the letter clarified my relationship with her, and allowed me to let go of certain expectations I had. Another was a couple of years prior, to my then-husband, and I actually sent the letter to our couples therapist. That letter also acted as a clarifier, because it helped me, and our therapist, see where we needed to go - in our very next session we amicably agreed to split up, much to our great relief. The issues in my letter didn't need to be discussed, because the result of writing it is that I had finally acknowledged to myself that I was ready to be done.

So... it depends on your goal, and it also obviously depends on the nature of the relationship, from the intimate and legal connection of spouses, to work relationships, and everything in between. However, being realistic about the other person is essential. Many people think they "need" to confront the individual who is harming them emotionally, and they sometimes do so with the expectation that the letter or conversation is going to change the other person.
(1) that's usually not going to happen.
(2) the real goal of this work is to change yourself.

Once you've changed yourself, you can reassess your relationships, and go on from there.

~Jan