I think you could benefit from going to some therapy for that anger and insecureness. Seriously, you cannot and should not forbid your girlfriend to talk to her friends. You have an abusive relationship and I'm afraid it's only a matter of time before you'll punch her. You're not ONE person, you're TWO persons with each your life who should have something lovely to share. Instead, you're controlling her and she is probably scared of you. I'm sorry, but she deserves something more than you can give her. You shouldn't be in a relationship until you have learned to control yourself and realise you're good enough.

The reason she's lying is because she's scared of you. She's having friends and trying to have a life outside of your relationship.

I think the real quesiton is, whether SHE should give you a second chance or not. And she shouldn't..