First things first, no matter what is going on you need to give her complete space at this point. When women get in arguments they like to think and think oh yeah and they like to think so more.
Women need to reevaluate the situation vent to girlfriends etc, this can sometimes take a few days to a week. By giving her the appropriate space(not contacting her in any way or fashion) you are allowing her to be able to heal and perhaps let you take her back. I know this doesn't seem logical but in the long run you will keep both your dignity and maybe even the relationship(if you have the patients.) Cause right now the relationship is in her court and hers alone.
At the same time this will give you the chance to not look so clingy/desperate and maybe even bring you into some good habit forming. Being neeedy is a complete turn off to all people in most situations. It makes you look and sound like you have nothing better to do/have no life. Now i know this isn't true you are a vast being! Start yourself into some interesting hobbies and meet some cool people. That way when shes hanging with friends you have some of outlet of your own and it will be completely equal.
You are going to want to keep busy, because thinking about her all the time is only going to make you want to contact her or one of her FRIENDS! Do not by any means contact one of her friends this is guy code! This makes you appear like a stalker and makes you seem like a very drastic and antcey person! Keep your mind on other things, hangout with friends play video games, exercise!
Usually the reason why women want to hang out with there friends is basically because they need time/space away from you. Dont take this as an insult Its nothing personal. You would probably expect her the same right! How would you feel if she got mad at you for hanging with your friends? You may feel some resentment!
Another reason can be because things are getting very routine or boring! Thinking back im sure you could identify alot of routines such as this that made you seem not so enjoyable to be with! Keep things fresh switch it up from time to time. Dont always eat at the same restaurant. Dont always call her the same names. Dont always give her the same generic compliments. Women like effort! Make a point to do something you have never done with her or talked about, every time you see her. How great would it be for you to seem incredible fun and spontaneous!? I would definitely like to hang out with that kind of person any day!
Relationships are like fish you need to give it space in order to grow! As far as the hanging with guys stuff, you need to treat her hanging with other guys like its nothing. That not even in a million years could she get a guy as good as you. This is going to keep you in confident mode and she is going to be like "he trusts me fully aww i wouldn't ever cheat on him, he is so confident in us!" Insecurity can give people reasons to look elsewhere so don't do it! By all means at least fake confidence! Switching the situation to make her understand by telling her you are going to hang out with some girls will also put some reality on the sitation! and maybe she will be able to see where you are coming from!
Now that you screwed up things big time

Use this time as an opportunity to think about what you want? Do you just like the idea of hanging a girlfriend? Do you really want to be in a relationship with someone that is so quick to pull the plug? Do you want a girlfriend that hang up on you and doesn't respect you?! Listen to your instincts when you answer these questions to yourself and do not use excuses!
Last but not least when she decides that she wants to talk to you again, don't be so quick to say yes. Keep her wondering(atleast a day or two) This transforms the power back to you! This will also make you look super attractive. Keep you head up and be confident, know that it will all work out as long as you play your role right! I have seen too many of my friends fail by not being able to stick it out and be patient! Make her beg you to take her back!
And heaven forbid if you are still waiting for her after a month or two, i suggest you to move on yes move on. This means stop caring, stop thinking about her and stop thinking about being mean and wanting to kill her new bf. 100% of the time after you break up with someone you just miss the routine of seeing them, alittle jealousy arises but just get busy and time sorts it all out. Then and only then it becomes easier and easier to heal. Getting stuck on a girl has no benefits, It can make you miss out on a ton of other opportunity's and can keep down and out for a long time! Dont become obsessed with this small failure because its infact not a failure at all. You succeeded in dating someone you dont want to be with! 9482982984298 more to go

! Love sometimes has to fail so you can grow and prevail!
Keep me updated on this