Dogtrousers
Kilometre nibbler
Outright pain ("torture"), as opposed to just heavy weariness sounds more like cramp than just exhaustion to me. If you've eaten well and had a good drink beforehand I wouldn't have thought you need more than a quick nibble and regular sips from your bottle, esp in current temperatures.
All I can suggest is lowering your effort level a bit, slowing down and enjoying the view (misty fields can be quite pretty). But I'm not an expert of any kind, so it's best to ignore me.
All I can suggest is lowering your effort level a bit, slowing down and enjoying the view (misty fields can be quite pretty). But I'm not an expert of any kind, so it's best to ignore me.