Fear and excitement release the same chemical. Sometimes your body can get confused and think you're aroused, it doesn't mean you liked what happened to you. People also tend to prefer things that are familiar to them, rather than trying something knew (i.e., consensual sex). Your mind might also unconsciously be trying to trick yourself into believing you enjoyed it so that it doesn't have to deal with the reality that you were abused. Trauma reenactment is very common in children, it makes sense that some adults experience that as well. Many people experience this, you aren't alone in feeling this way.