In terms of the D, follow what LH told you. That is spot on. If she files, she files. You can't control that. You can control what you do. If you don't want a D, don't file.
Do you have a reason to think she is having an A, or is this just fear projecting? Obviously don't validate an A, but you don't want to react emotionally either. You are the lighthouse. No matter what, A or no A, your W is acting out and damaging the relationship. You need to personally decide what that would mean to you in terms of continuing to DB, or letting go once and for all. But don't do that in the heat of the moment. Let it sit.
W 34 Me 42 Married 7 years together 8 0 kids 1 beloved dog BD 4/6/2018 I moved out 4/7/2018 I moved back in alone 8/05/2018 I file 3/06/2019 D official 5/7/2019