Afraid Of Our Future

I’ve been dating my boyfriend for just about six months now. I know that I want a future with him, but it’s so difficult considering the situation we’re in. He’s apart of the LDS Church and his parents despise me, especially his mother. She hates me because I’m not apart of her church. It pains me that she judged me purely on that fact, but that’s just the way it is. His mother is emotionally abusive. She has called him a faggot, worthless, a waste of oxygen, etc. and has shamed him for the way he is. Not to mention, he’s adopted. Her actions have caused him to feel incredibly low, to the point of attempting to end his life & run away from home. Soon, my boyfriend’s going to have to go on mission. But, he won’t be allowed to because he has committed “sins.” Once he graduates, he plans to go to Utah and live with his sister and brother-in-law since he won’t be able to afford an apartment where we live. This makes me incredibly sad because I won’t be graduating until a few years from now and I don’t want to feel the pain of a long distance relationship. It’s heart-wrenching knowing that he’ll be gone in just a few months. I love him more than the stars and don’t want to imagine life without him. How can I cope & prepare for the future?