You were hurt and healing that injustice is hard. As much as people think they can move on it doesn't always happen. Also, do u think that knowing he's had intercourse relations with another woman while you refrained of intercourse with your new guy could be adding a hint of jealousy? Are you thinking you should have just gone all the way? It's normal. Those are called human feelings! Everyone is conflicted with strong emotional attachments to new and exciting avenues!
Fear not! You are not alone. And no I don't mean the aliens are coming.