But I think you need to work on better "opposites". E.g, "as of now" and "long ago" don't really seem to be opposite. Instead, maybe they're complex conjugates of each other. I.e, they have similarities along one axis (time frame) and differences along another. But I wouldn't consider those two to be opposite one another. Word2vec with a consine similarity closer to -1 might be better than what you're using now.