No matter what I do she has no trust and doubts everything

She doubts when she has no reason to

Are you entirely sure about that? Infidelity is not limited to the physical act. There must be some reason she has distrust. Unless you acknowledge it there is no gaining back trust. You need to sit down with her and have an honest conversation about expectations and boundaries. You need to come to an agreement and mutual understanding. Otherwise there is always going to be this difficulty. Something that might seem harmless and innocuous to you could be seen as a major threat to her. You need to acknowledge these feelings she has and come to an agreement and stick to it about actions on both your parts.