When you accidentally communicate intent, you communicate that you are in great pain and need help. If self-harm or suicidality are among your symptoms, I personally think it is best to have a specific agreement with your therapist, stating if this happens, the consequences will be this, so there will be no hurtful surprises. You need to take responsibility for yourself and not give it away to someone else. By consequences, I don't mean punishment, but an agreement that safety comes first. It really is best for both of you because if you are feeling betrayed by him, then he is probably also stressed being forced to make a decision regarding your safety that is going to make you feel betrayed when safety, not betrayal is his intent.

When you agree to a plan, than you shift from randomly bringing trauma into your life by forcing others to respond to you, even accidently, to making a decision for yourself for what will happen next. The responsibility for your life returns to you where it belongs. I hope this doesn't sound judgmental because I have had to learn the same lesson.

When we have a hard time letting go of a behavior it is because it is doing something for us. You probably know what the harm is doing for you, and suicidality serves to make us feel in final control when we cannot get our life or emotions in control, but what does accidentally communicating intent do for you? If you could be completely honest with yourself, what is it that you want or need from him? Understanding this may be your first step in moving beyond this.