Your girlfriend was hitting the wall and wanted to get some last great sex in before deciding to settle for you. She knew that those fun opportunities were about to disappear, and then you came along like a bank machine she doesn’t have to respect. I think it comes down to your girlfriend being an entitled whore who thought she could have the alpha fucks and beta bucks both at the same time, hence the overlap in your relationship. You lost 4 years, but you just gained your life back. Consider yourself lucky you found out the truth before you bought the ring.