I totally understand and throw in any health issues and BAM we have health anxiety. If you doctor won't listen go to a new psychiatrist. Your doc should be more then willing to switch you to a new med. Many people need changes after time.
You will get through this, I have been in your shoes, I know how much we miss that calming time but you can find it again.
Yeah fighting anxiety can be very tough at times. But you've fought it this long, and even though you feel a little defeated, its temporary. Have you tried therapy. Specifically cognitive behavioral therapy, i've found to be really helpful. It helps you understand that a lot of your thoughts are very inconsistent in one way or another. Once you recognize this then you can learn ways to change your thinking reducing your anxiety, and it helps you deal with any issue that that disturbs your peace. Also deep breathing, and exercise helps a lot. You will get that peace and calmness back, just do the right things for yourself, and try to walk through your fears. I don't know if you believe in God, but prayer and meditation can be very comforting. Take care.