I have been practicing the JournalSpeak method. I write, trying to maintain focus on how I feel and I write unfiltered. I then re-read it once, I find that the insights I've had and the emotions it dug up for me can be better felt reading it once through right after the fact....at least for me. Then I delete it.
One of the basic "principles" I've enacted in my own healing is that if something make me uncomfortable or anxious, I lean into it rather than avoid or run from it. You may have gotten the words out on paper, but your mind still views those memories or thoughts as dangerous. Not to say that could be solved in one re-read, but I've heard many people refer to journaling as a form of exposure therapy. You're "exposing" yourself to all of those thoughts, emotions, and memories that you've buried or avoided, and the more you do it, the less power they will have over you in time.