This may seem obvious, or tautological, but one of the functions of psychotherapy is, through talking about something, becoming comfortable with some difficult part of your past, or past imagination. Thinking about something is one way of engaging with it, but talking it out is really the best way to de-fang something difficult.
So, I’d say two things:
First: A therapist that you really trust, or can come to trust, is a key part of the healing process. Mine mostly just listens, but will provide some validation when I ask for it. There is nothing I have ever said that has caused him to register shock on his face (well maybe not never, but he’s got a pretty good average).
Second: Modern audio recorders, on your phone or computer, can be pretty useful once you’ve gotten to the point with the therapist that you are out of danger, and acting within the bounds of normative behavior. It is userful to just say aloud, “boy, I got into some really ugly shit on PornHub last night [or for that matter 25 years ago on it’s analogue]”, laugh about it into a recording, and think about past trauma… well it goes a long way towards taking something out of the dark, dark recesses of “thinking about it” into the much more healthy air of “talking about it.” (Even if it’s just so you can hear how normal your own voice sounds, and how usually banal the story is in playback.)
Writing is healthy too, but be, as Kay Redfield Jamison says “circumspect” about sharing on a blog or social media, for the effect it may have on employability and such. (KRJ is a PhD psychiatrist, and tenured faculty at Johns Hopkins University, so she’s got a safe platform from which to talk about her personal experience of mental health. As she says “being on the psychiatry faculty explains everything.”)
One problem I have faced when engaging with this process of what I’d call “psychotherapy journaling”, particularly as a technologist, is this paranoid need to record in a medium that no one can ever see, hear, or read. The reality is that once you get more familiar with airing something that feels deep and dark, and seeing how funny, normal, weird…etc it is, you get more comfortable with just laying it down into any available medium.
You don’t need a 300 pound safe or 5 thousand bit encryption for your journal.