Best Friend Trouble ( Help)?

Well my friend she's been hanging out with this other girl and I dont really like this other girl very much.I kinda felt like she was distant from me because last week she went to mall to get a dress for formal with another friend when she promised we would go togther. so i waz kinda mad about that but i let it go. Then yesterday I was in a bad mood so I said somthing cold to her and now shes all mad and today at lunch she was cryin and everything and she said that i always take my anger out on her and im distant to her and stupid stuff like also beacuse i didnt hug her oneday and say hi to her in the hall. Were really close and I dont want to lose her as a friend ecspially over somthin this stupid.So what shoud I do ?