Fiancé WONT stop accusing me

My fiancé has done hella shady shit in the past and we have gotten over it and he has changed or I wouldn’t still be with him. But now he’s starting to accuse me like everyday of going behind is back. Im so sick of it and it makes me feel like he’s doing something so im like what the fuck! He does suffer from anxiety pretty bad so that’s what he chalks it up to.

Have any of you had this experience and they WERENT going behind your back?

He is completely open with his phone. I have his location. Idk how he could go behind my back but there’s ways.