I am 33 years old and have been timid and panicked since I had my gallbladder removed in 2009! I get very flustered when I hear loud noises while sleeping! Also accompanied by increased heartbeat...

This is a psychological problem. I suggest you see a psychiatrist. It has basically nothing to do with the internal organs. Or try some soothing drugs. Watch less scary movies. If you really can’t sleep, sleep with your family. Or sleep with the lights on, which will make you feel safer. Read jokes before going to bed to relax your mood, and exercise more