Before telling a hard personal story publicly, decide what the story is for, what you are willing to have permanently associated with your name, and who else appears in it. Tell it from a point where you have some distance. Other people in the story did not consent to being in it, and that constrains what is yours to tell.
A practical test is whether you can edit it — cut a section, reorder it, leave something out — without distress. If the material still has to come out in a particular order and at full length, it is likely still being processed rather than shaped.
Legally, usually not for your own recollection. Ethically it depends what you disclose: your experience of a relationship is yours, while another person diagnosis, private conduct or identifiable circumstances are largely theirs. Where you can ask, asking is generally right.
No. Every telling is a selection, and choosing what serves the listener is editorial judgement rather than deception. Dishonesty is asserting something untrue, not declining to disclose everything true.
Then weigh what the story is for against what the exposure costs them, and look hard for a version that keeps the meaning while removing the identifying detail. If no such version exists, that is a real reason to hold it, not a failure of nerve.