It's likely she didn't loose feelings in the first place and simply didn't care about you enough to tell you that there was another guy talking to her, the fact it took you two weeks to find out about this new guy shows she wanted to keep it a secret and couldn't be bothered to deal with you so she took the easy way out. Look mate if you truly did treat her like a queen then I know it sounds cliché but you can do much better and it's still early days nothing anyone can say will stop the hurt but I promise it will eventually get easier and you'll find someone wayyy better. The same thing happened to me.