Most of our bitterness and anger towards others is rooted in an inability to be profoundly amazed at Christ's love for us in our sin. If you are struggling with bitterness then it may be that the Lord is letting the very sin that is flowing from your inability to see Christ be the means by which you come to see him. In other words, perhaps this season of rage, anger, and a fed-up 'I'm out of here and don't want anything to do with you' spirit is where you have had to come in order to see the greatness of your sin as a forgiven and justified saint. And the Lord has done it so that you would be stunned at his grace in a deeper way than you've ever been stunned by the grace of God before. And now, out of that experience can flow grace towards others.