Thank you for your letter -- and for your contributions not only to our nation but to the life of your church. Even if people there aren't as friendly as they should be, your life is a reminder to them of the suffering believers often face in other countries.
You're right: Those who love Christ should also love others, regardless of their background. Perhaps your letter will encourage church members to do this more openly. The Bible says, "The stranger who dwells among you shall be to you as one born among you, and you shall love him as yourself" (Leviticus 19:34, NKJV).
I often think of Jesus' little band of disciples. They were a very diverse group: Matthew, who had collected taxes for the Roman government; Simon the Zealot, from a group that hated the Roman government; Peter, an ordinary fisherman -- and so forth. And yet (with the exception of Judas) they were united by their love and their commitment to Jesus. Jesus said, "By this all men will know that you are my disciples, if you love one another" (John 13:35).
What can you do? First, gain all you can from your church, in spite of its shortcomings. Take notes on the pastor's sermons; let him know you are praying for him; seek out a Bible study or class where you'll learn more of God's Word (and also can meet others). In addition, ask God to help you reach out to others in your city (including immigrants from your own country) and encourage them to follow Jesus.