That's sad you can't see yout mum, but that is a very long drive.
Driving is a very major trigger for my fatigue so I can't do any long drives anymore, they are too exhausting. I can make it there but the brain fog means I don't feel safe for the drive back. It's very restricting and sad, I used to love to go off on my own across the country to gigs and events.
I still get away now and then but it takes a lot more planning. I always use the train if possible, it takes longer but I do not have to have my wits about me so much. If I can't take the train I try to break up a long drive with overnight stays somewhere nice, and make a little road trip holiday of it rather than just one long trudge there and back. It does make it expensive, but means I do get to see far flung friends and family occasionally.
Is there any alternative to driving to get to your mum @MewithME ? If you plan ahead the train can be cheap.