Do not start by deciding to trust again. That decision is the last step, if it comes, and it is yours. Nobody who broke something gets to schedule your forgiveness because they are tired of the consequences. And nobody who was hurt has to perform suspicion forever in order to be taken seriously.
If there is coercion, monitoring, or fear about what happens when you tell the truth, stop here and use the safety resources in HLL Find before you read the rest as a plan. Repair talk can be used to pull you back into a situation that is not safe. This article assumes you can say no and leave the conversation.
What not to rush
Outside help belongs early with trust, not as a last resort after you have already promised a reunion you do not feel. A licensed person, or a serious support line if you are in danger, can hold facts you are still too raw to sort. You do not need a complete theory of the relationship to make that call.
What you can ask them: help me tell the difference between a broken agreement and a dangerous person. Help me see what evidence would matter. Help me not make a permanent decision in the week the news arrived, and help me not pretend the news was small.
If the other person wants couples work immediately, you can decline until you have had your own conversation somewhere the story is not being managed. Wanting to be believed is reasonable. Wanting the clock to start on your healing is not something they get to invoice you for.
You do not owe a timeline. A rush toward "we're good" is often another form of the original erasure.
What was actually damaged
Trust is specific. "I don't trust you" is true and too large to work with. The workable version names the agreement. You said you would tell me if you saw them. You said the money was in the account. You said you were at work. The damage is the gap between the agreement and what happened, plus whatever you had to discover alone.
There is also the second damage, which is easy to skip. After the fact, did they tell the truth when asked, or did you have to assemble it? A lie about the event and a lie about the lie are different sizes. People often try to repair the first while repeating the second.
You can hold two things. They may have been frightened, ashamed, or careless rather than cruel. The effect on you can still be that ordinary sentences no longer feel like ground. Impact does not have to cancel intent, and intent does not have to shrink impact.
Name the agreement that broke. Trust returns, if it returns, to that agreement, not to a mood.
The next true thing
Ask for one true account of what happened, in plain sequence, without a speech about why you should be over it. You can write your questions down so the conversation does not become a hunt. What happened. What you were told. What was left out. What they will do differently in the next similar situation. How you will be able to see that, not just hear it.
Then decide what you need in order to live through the next month, not the next decade. Separate bedrooms. Shared access to a bill. A pause on a friendship. A delay before any talk of recommitment. These are conditions, not punishments, and they can be time-limited.
If they refuse a plain account, believe the refusal. It is data. You do not have to call it closure. You also do not have to keep interviewing someone who has decided the interview is the injury.