I'm a girl... Let's see if I can help.
eTronicGaming: what was the lie she accused you of? Cuz sometimes is something you think is silly but actually aren't... But maybe, if it isn't anything that comlicated, u could try to give her a little time, thenmake her something nice, or just try to talk personally... That if you want her back. If not... well, let it dies for a moment, then try to talk see why she got mad at you. BTW... NEVER EVER tells a g/f that you just wanna be friend.. That's almost impossible and actually hurts a lot. It's like "I know I made something wrong, but instead of talking and solve that i prefer just to be your friend and we forget the rest". It can never mean that... but it seems...
HerLoss: this girl you described sound really crazy... What was the exact accusation she made? And if she goes out with so many people, then you should really make tests...
awesomegamer: better for you. I just thinks that a g/f should like same things as you and respect your choice... same thing to b/f... If the person doesn't respect you, it might hurt, but it'll be better later...