Hey Kitty,
Being 55 doesn't have anything to do with being tired. As someone else stated at age 45 something went haywire for me---no energy, depression,etc , etc...Discovered at age 45 that I was in menopause! So first off make sure you are well.
As for stressful work---I was an industrial engineer in the trucking business. On call 24/7 in a business that didn't know the meaning of "detail". Everything was quick, down and dirty---get 'er done! Imagine the difference between that and quilting....
I have really had to retrain my brain to do detail, clean work; but it wasn't easy. GO SLOW...learn to enjoy your alone time. Put on soothing music or keep your sewing room quiet. It can be an enjoyable release for you after a stressful day at work.
Roxanne