You really have no memory, yet you are an expert on me, with my sayings as your footers.
Dan 8:13 is about the rebellion that happens in the 4th kingdom that comes, and it is later called the abomination, because it was, and it would ruin the country. In Dan 9, it has a timestamp on it, and is contrasted to Messiah who sacrificed himself. The act is done by perditious Jews and they cause the ruin. It is not done because of Romans, although Romans are the army that desolates the land.
You need to start from scratch on NT background.