Part of our courtship dances is each partner growing trust, at their respective paces, that we can feel predictably safe with each other, in many situations. I'm growing to trust that I can show you honestly who I am, warts and all, and that you'll steadily accept me with real compassion, empathy, and love no matter what. At least two sets of things. The second of two things typical mates want is self trust. If one or both of you are ambivalent or skeptical about this, your options are limited.
Specific distrust is easier to rebuild or accept than vague distrust.
See the examples above for ideas. If it doesn't, then live with distrust without complaint. Truly rebuilding trust is a second-order change. I don't know how many months, right now. The first place to look is toxic shame , usually expertly camouflaged.