Hi May-
I am also 51, and had a hysterectomy and am hypothyroid and none of those things have stopped me!
I have more energy, not less, on CALP than before. I have no suggestions. PP is a great plan- and another one is Schwarzbein to heal your body. SBD is also excellent, and I guess it is a YMMV issue. I do eat lots of protein, veggies and do balance my RM much more than most people- works for me.
Please post so we can help. I do this for my health, adn don't focus on the weight as much. It is a slower plan, but for me it is a WOL.
HTH-
E