I know from my own experience that the fatigue associated with PBC can be life altering.There is so much we can do , though, to help ourselves.
Arrange your days so that the majority of your calendar is in the morning. Many people say that by afternoon they are 'done for'.
Don't overload your days.. give yourself a day of rest if at all possible.
Try to work some exercise into each day. Not running a 5k or even jogging for a mile ( great if you can do that though) but even just walking around your house, plan a walk from one point to another, watch a utube on chair yoga ( I love chair yoga), moving is what is important.
I can remember all too well how hard it is for me even now to 'move' on those fatigue days. Seems an accomplishment just to get dressed much less go for a walk. Be kind to yourself. Keep your goals realistic. Important not to set yourself up for failure. Some days you might not get off the couch. That's ok. Do what you can - when you can.