Don't do too much at once or you will jump each time you look in the mirror ;-).
Look at the various websites for hairdressers in your area to see if any have wigs to try on? That's what I did prior to having my long hair cut. Initially I went from waist to shoulder length then to a short cut with perm - looked like Crystal Tipps and Alaister ...... my boss didn't recognise me
So I would get any split ends tidied up and maybe a couple of inches off initially. See how you feel. If you can try a wig you will see exactly what the lengths will look like. U can then decide how much to have cut off the next time, is there any rush?
I think that shorter hair looks better on ladies as we age. I stopped having my hair hi-lighted here at home 6 years ago and because my stylist cuts well, it has gone grey gently so that I am used to it.
Also if the hair is coarse a good stylist can 'strip' it back by cutting it sympathetically to lighten the look. A good conditioner. A scalp massage is lovely.