Many churches today find themselves in the midst of what someone has called the "worship wars"–and it sounds like this struggle has come to your church as well. Let me make just a few comments about this.
Yes, I know you feel like you have lost your church, and I understand why you feel this way. But in some ways it sounds like you may actually have regained your church! You see, from what you say your church may well have been on its way to dying.
But now it isn't dying–and you should be grateful for that. No church can survive for long if it refuses to reach out and bring others to Christ. Jesus' words in one of His parables are just as true today as they were almost 2,000 years ago: "Then the master told his servant, 'Go out to the roads and country lanes and make them come in, so that my house will be full'" (Luke 14:23).
Make an effort to get acquainted with some of the new members in your church, and ask God to help you be an encouragement to them. Remember: At one time you were their age, and someone older probably helped you learn what it means to walk with Christ. In addition, pray for your pastor, and as you have opportunity, encourage him not to forget the needs of the older members also.