Write from facts rather than momentum
Pause long enough to remove accusations, assumptions, and details that belong to someone else. For a message about how to apologize for giving unwanted health advice, use this factual base: name the missed care, privacy breach, exposure, comment, or accommodation and its practical effect.
Offer a proportionate next step
Match the size of the request to the relationship and to what the recipient can reasonably decide now. Correct what is still correctable and ask what support is useful rather than prescribing it. Make the immediate next step clear enough that the recipient can answer without reconstructing the entire history.
Protect privacy on both sides
Do not debate symptoms, disclose medical details, or make the person reassure you. For urgent symptoms, exposure risk, medication errors, or safeguarding concerns, contact the appropriate clinician or emergency service. Use the most private legitimate channel available and do not share the exchange to recruit support or pressure.