To be specific, the said she was going to the movies "alone" and got a little miffed when I seemed to not believe her. She said I was "acting" like I always do when she goes out. Funny, this time, I really believe I was not.

You just wrote that you "seemed to not believe her". That's what she took notice of. What did you do? There's your next 180 project for you in that answer.

So we are at a point where my W seems to be asking me to believe her when she says certain things, and her actions most of the time back up what she says. Do I just believe her? Do I just write it off and try to not even consider the situation, just DBing my way through it?

"most of the time" suggests to me that you still have situations where her actions don't match her words? Thus, trust is an iffy thing to hand over without a consistent firm basis, no? You don't have to trust her right now. Your granting of trust at this moment is not the issue. Acceptance is. Swap "acceptance" for "trust". Accept her at her word, let events play out, and evaluate them, keeping an eye open, and see if she continues giving you reason to build trust step by step.

Trust, for you, will never be of the blind kind again. And it's better that way.