Funnily enough i was talking to a bloke at work a few months back, who runs half and full marathons, and he's 56 (the bastard

) and he's convinced my issues are mental. Says there no way a bloke who can do the first 10k in 40 minutes should hit a wall at 13k and be basically run / walk / running shortly after. The plan for this summer was to spend some time training with him. But that went south.
Next GNR is mid sept so registration is well past, but if i can get running again soon there's heaps of time to prepare for next year.
Sounds from your plans and aims you have the bug too. I'd have been amazed ten years ago if someone told me i'd spend my time running through the countryside.