I'm not yet forty but I think starting over is so awesome and courageous at any age :) you should probably go back to school then :)
Well I'm 40 and divorced , I want to go back to school but I feel too old. i want to get a better job and be proud of myself but I'm afraid I'll get sick or something entering my 40s?
Edit : I want to never mind about answering this then ;)
I think you need to see your doctor.
Stop listening to others and get the correct information you need to treat whatever you may have.