PIP - Planning and following a journey with extreme fatigue

I wonder if someone could give me some advice regarding the Planning and following a journey part of the PIP form.
I have lung impairment, postural tachycardia and chronic fatigue. My main issue is extreme fatigue which makes me unable to walk more than a few metres without worsening symptoms. Most of the time I don't even have enough energy to be sitting up in a wheelchair for sufficient time to take any journey. I'm not sure though if I should choose the descriptor F which says 'cannot follow the route of a familiar journey without another person, assistance dog or orientation aid'. I don't need orientation aids, I need someone who pushes me in a wheelchair, but that still doesn't make the activity safe for me as I crash afterwards and it takes days/weeks to recover. Descriptor E says 'cannot undertake any journey' which is correct, but it is not psychological distress that prevents me from going out, it's all physical. Any ideas how I should approach this question?