I can understand your hurt, and I'm sorry some in your church are suspicious of your commitment to Christ. But God knows your heart, and I hope you'll never forget you now belong to Jesus, and that no one can take that away. The Bible says, "The Spirit himself testifies with our spirit that we are God's children" (Romans 8:16).
Your letter reminded me of what the Apostle Paul experienced shortly after his conversion. Before he met Christ, Paul was determined to destroy the Christian faith and persecute anyone who followed Jesus. All that changed when he met Christ -- but at first the Christians were suspicious of Paul and felt he was only pretending to be a believer so he could discover who they were and arrest them.
But Paul didn't get discouraged or give up his faith -- not at all. He knew God had forgiven his sins, and that he now belonged to Jesus. And God graciously sent him a Christian friend by the name of Barnabas, who was able to persuade others that Paul was now a committed Christian (see Acts 9:26-28). Ask God to send you a "Barnabas" -- a Christian friend who can encourage you and help others realize what's happened to you.
But Paul didn't just rely on the testimony of his friend Barnabas. Most of all, he showed by his changed life that he was now a follower of Jesus. May this be true of you.