I'm glad it's not just me who hurts in a 10K; I guess anaerobic running for 6.2 miles will hurt no matter what your pace. The only thing I've learnt through doing more 10K's is that although my lungs are burning more or less from the start I can sustain the pain, just about, until the finish!
Thanks for encouragement, am not writing this from therapists office, I have a long term plan for the Bob Graham.
This year and next, at least one mountain marathon a year (Swaledale this year, 2 day next year).
Over next 2 yrs, run each section of the Bob Graham.
All the local LDWA events which are typically 22 miles on the fells and I do at the sort of pace you need for BG.
Pace individual leg of someone else's attempt (you need 1 pacer and 1 navigator per leg typically).
Train like mad for the final year (I've also got 4 yrs until I'm 40, yikes no, it's nearer 3 now!)
Last but not least get my business to a point where I can take one day off/week to train while someone else does my work!
Sorry to go on, now I've written it down it feels more realistic.