Sacrifice in a dream is symbolic: giving up one thing so another can live or grow. It is read as a hard choice, or as the feeling that too much is being asked of you.
Where in your waking life have you met something like this lately?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.