I need advice! Help!

So I'm in a relationship with this guy. I absolutely adore him and I want to marry him eventually. We've discussed this with eachother many many times. Recently though, my adoptive parebts told my biological parents to break us up and since I am still under the adoptive parents custody I would either have to hide the relationship from the adoptive parents or my parents are going to break us up and I really don't want that because I love him with all my heart. I don't know what to do. He's helped me through so much stuff like anxiety, depression, self consciousness, and helped me recover from sexual abuse fron a former guardian. I know he cares about me and makes me happy. Please help...