I know it's hard to see the forest thru the trees, and ALWAYS easier on the outside looking in, but . . . if it were me . . .
My purpose would be something along the lines of "To finally have the courage to hold up the kind of marriage I am willing to live the rest of my life in, and hope and pray that my husband comes along and joins me in working at that and abiding those boundaries, but if he doesn't, to be strong enough emotionally, spiritually and financially to know that I'll be okay."