Most Helpful Girl
You have to let go :( That we can still be friends thing... it only works with mutual break ups. I know you don't want to hear this, but she doesn't need to give you a reason why. And if you have to talk someone into getting back together, it won't last. I'm so sorry, because I know it hurts.
Most Helpful Guy
It sounds like you're not really paying much attention to her.
You seemed happy. She did not. That pretty much sums it up.
Did you even notice that she wasn't happy? If she's your girlfriend, you should understand her emotions enough to know when she's unhappy. I can tell my wife's mood without even seeing her as soon as she walks in the door by the sound of her footsteps and the way she closes the door.
Obviously, nobody is happy if you two are arguing daily for 3 weeks. While every couple argues from time to time, a daily argument usually spells a relationship breakdown. Your behavior in those arguments will also play a major role in what she thinks of a future with you.
If you are like most men and have a gigantic ego and refuse to lose an argument, your relationship success will be low forever. Many men with large egos NEED to win an argument. This means they value their ego and pride more than the girl. They would rather humiliate their girlfriend and make her feel wrong, rather than suck up their pride and come to a resolution. I would say neither party is right or wrong in most arguments. What's important that the argument end in a manner where you two still talk to each other afterwards, instead of sulking away and not speaking to each other for hours or days.
Phrases starting with "You never..." or "You always..." are the wrong ways to argue. Basically placing blame on the other person. Like "You never wash the dishes". Yet, I'm sure such a statement is untrue because both people I'm assuming have washed the dishes at some time.
My advice, and this is probably the greatest advice you'll get in your entire life...
When you are talking to someone, whether it's a conversation, argument, negotiation, bartering... etc... Focus...
Ask youself what your goal is. If your goal is to win and humiliate her and lose face with her. Then you've achieved your goal and the breakup is your reward.
If you want her, or future girlfriends to still love you after an argument, then determine what outcome must result for this to happen. If she's only happy if she wins, then bite the bullet and let her win. If she only needs you to see her point of view, then acknowledge her point of view and do not push your own upon her.
Most guys act first and hope that the action leads to the result they wanted. Few are wise enough to determine what action must be made for the result they want.