I have been diagnosed with clinical anxiety. I have been anxious all my life but recently it became extreme to the point of shaking and freezing. I am always asking the question “What if and what will thus be the result of it.” I am very involved in several activities at the Lord’s church and tell others how to be saved and live the Christian life. I very much believe that I can do all things through Christ. Why do I continually put myself through this? It certainly does not lead to peace. I sincerely strive to please God in every way and follow the commands of Christ. Do I have a personal relationship with Jesus under there conditions? I know of those who have this problem and eventually lost their heavenly reward. I am so fearful this might happen to me. I am reading and praying so much more now than I ever have. What more can I do other than learn to trust more?
While this answer specifically answers the idea of a fear of death, it brings up a number of points that can be applied to a generalized fear. See: How can I overcome the fear of death? Clinical anxiety can be caused by hormone problems, such as a thyroid disorder, so I assume your doctor is looking into the underlying cause. What you need to realize that just because you feel a certain way, it may not be the reality of the situation; though, I admit it might be hard to distinguish since feelings are very personal. In addition, we are judged by what we do (Romans 2:5-7). Your feelings do not determine your relationship with God.