Maku, I went through a similar thing. My mother-in-law moved into my house and convinced my wife that I was looking for other women. I wasn't and was just extremely dissatisfied with how the relationship was going. However, my wife kept believing it, to the point where I very nearly had an affair since I felt that if I was being punished for it I might as well do it.

In the end, there is nothing you can do to convince her. Continue to tell the truth and continue to stay chaste as long as you're in the marriage. But for me, I had to improve my mental health and well-being and in the end that meant terminating the marriage.

Concentrate on your mental health and either your woman will come around or you'll find one better suited for you.