Sorry to hear that you feel no reciprocity of sincerity from your siblings or lover. What can one do? People are who they are.
Perhaps your siblings have lost respect or are themselves unable to really be true to their nature. A great book to read is "Everyone can Win" outlining steps to help one gain strength in one's beliefs and ideas through constructive methods of voicing one's opinion. The book was developed in order to foster world peace which is what is so lovely about it. It is suggested to have it by one's bedside and study it regularly. After a while you find a certain amount of composure realising that not everyone is the same, and that you still have a right to your individualism , your voice.. If you feel your chosen partner is not there for you I would question what it is that draws you to them. No one is perfect however reciprocity is so important in establishing true and long lasting loving relationships.
Much love R