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 support someone after canceling a wedding, use this factual base: acknowledge the loss as they describe it and notice the immediate housing, childcare, work, or social impact.
Offer a proportionate next step
Match the size of the request to the relationship and to what the recipient can reasonably decide now. Offer one practical task or a form of company that does not require them to retell the story. Make the immediate next step clear enough that the recipient can answer without reconstructing the entire history.
Protect privacy on both sides
Do not attack the ex, push dating, demand details, or share the news before they are ready. For abuse, stalking, housing danger, child risk, self-harm, or immediate danger, connect them with specialist or emergency support. Use the most private legitimate channel available and do not share the exchange to recruit support or pressure.