Revert getting married.

I am a revert, and this man told me that he wanted to marry me. I made sincere dua for us to have our nikkah, and Allah (SWT) granted part of what I asked for, but I feel I may have taken that blessing for granted. Now his mother is refusing the marriage. She is concerned because my parents follow a different religion. She fears that any future grandchildren may be influenced by their maternal grandparents, and she also does not like the fact that she did not have the power to choose her sons wife. I want to speak to his mother directly, or that she would reach out to me, so she can see that I am steadfast in my faith and sincere in my intentions. I want her to know that I may potentially lose my parents as they disapprove, and I want a family, I want her to be a part of our lives. He is her only son, and she has threatened to cut ties with him and withdraw all support if he goes ahead with marrying me. This has deeply hurt him. She does not seem to realise that by being so adamant in her refusal, she risks losing him. He has said that if he is forced to marry someone of her choosing, he would move away from his parents entirely. His family has suggested that I move out of my family home and live on my own, but they do not understand how difficult that would be for me. When he told his family about the abuse I have been facing, they questioned why I do not simply involve the police if I feel so strongly about islam. This response has made the situation even more complicated and painful. My parents are also hurt by the choices I have made and believe that I am doing something wrong, even though I do not believe that I am. I am making istikhara day and night for Allah swt to soften his mothers heart.