Has anyone here changed careers later in life (like over 40)?

For years I have been contemplating a career. Right now I have a job and it’s not even a job I like. I want to do something in the medical field but I have no confidence, I’m over 40 and my math sucks. Has anyone here changed careers over 40? Done something they never thought they could do? Can I learn math well enough at this point in life to go into the healthcare field or it pretty much a done deal? I have been told that I am comforting and easy to talk to, so nursing (LPN or RN) might be good, or maybe PT or Respiratory Therapist. I hate my job! I do have experience in Mental Health field, Geriatrics and I’m pretty good at Medical Terminology (I like it). I have great communication skills and English and writing are my strengths (except when I’m on Fluther).