You can be upset if you want to. It bothers me that our world tells women to question their feelings. It’s sad to think that women may feel like their opinions are invalid or exaggerated just because men have said so. It’s okay to feel to any extent. You’re clearly upset, so yes you should be. It’s how you feel. He used you, and now he’s lying to his girlfriend. He’s scum. Throw a fit. Panic and freak out. Find someone to hug.