I think Ellen has given you great advice, but since you asked for experiences and opinions I’ll add mine.
I can attest based on my experience that journaling is not essential. I have never done it and I am no longer troubled by TMS or its equivalents even though I have a history of such symptoms extending over more than half a century.
Before turning to my opinions, I have an observation about Dr. Sarno and journaling. Unless I missed it, he never used the word “journaling” in any of his four books and did not say anything about writing-stuff-down until his third book, The Mindbody Prescription. There he wrote: “List all the pressures in your life, since they all contribute to your inner rage. There are self-imposed pressures, typical of the conscientious perfectionist or the goodist, and the pressures of everyday life, including ‘happy things’ like marriage and children since they, too, represent great pressure. You should also list anger left over from childhood. Patients have found this to be a very helpful exercise.” He said basically the same thing in his final book, The Divided Mind.
My opinion about why journaling can be "a very helpful exercise," as Sarno put it, is that if you set aside a time daily, say in the evening, to think about what happened during the day and how it affected you emotionally, at least you will be paying attention to your emotions. I prefer to do the same thing mentally rather than in writing because I can think faster than I can write and because I can easily do it throughout the day rather than having to take time out to sit down and write--and that is what I do.
I prefer an approach like Frances Sommer Anderson described in a book she co-authored with Eric Sherman titled Pathways to Pain Relief. Anderson and Sherman are psychologists who worked for years in Santo’s clinic treating patients of his who needed psychotherapy to recover. Sarno wrote the Foreward in their book. Anderson advocates taking a “feeling inventory” by asking yourself throughout the day about things that happened in the last hour or so. Here are several examples she gave: “How did I feel when my supervisee didn’t meet the deadline and casually brought the work into my office without acknowledging that it was late? How did I feel when our nanny called to say that she had an emergency and had to leave immediately, possibly indefinitely? How did I feel when our 16-year old son showed up two hours past his curfew, undeniably drunk?” Notice that the questions are not vague “how how I feel” ones. They are specifically targeted: “How did I feel when person A did x?” and “How did I feel when person B failed to do y?”
As for the worse-before-better thing, it is not clear to me that Sarno was acquainted with that. In The Mindbody Prescription, he wrote: “Patients often ask, ‘Won’t it make things worse if I concentrate on all the troubles and problems in my life?’ Paradoxically, no, for it is the failure to realize their impact on the inner mind that leads to such conditions as TMS, heartburn, migraine headache, anxiety, and depression. By identifying and dealing with sources of pressure consciously, you reduce their potential negative effect in the unconscious.”
I added the bolding in the last sentence above. It is one thing to journal about how angry person A made you when he did x, but what about the consciously “dealing with” part? In my opinion, which is not based on experience since I have never experienced worse-before-better, getting worse before better means either you have not consciously identified the real sources or have identified them but have not consciously dealt with them. So how does one deal with them? I will now go out even further on the limb I am on with a personal example. Suppose my wife makes me angry because she did x or failed to do y, and I don’t realize I am angry at her because I am repressing it. I take a feeling inventory and realize I am angry at her and why. Now that I have identified the source, how do I consciously deal with it? I realize that I am projecting my perfectionism onto her and expecting her to be perfect, and I also realize that my expecting her to be perfect is both unrealistic and counterproductive or, in a word, stupid. I also realize that if I were to act out on the anger, that would be maladaptive--or in the same word as before, stupid. So I either drop the matter or, if it is really important, negotiate tactfully with her about it.
