It always is the hardest at the beginning.
"How can I run for 19.5 more miles?"
"What will I feel like 2 hours from now"
"Will I be able to walk after this?"

These are the thoughts which circulate in my brain for miles on end. I
trust in my experience, my body, and all that I know makes me who I
am. My family, my friends, my body, all of it. It gets me to the end.

And it got me over three hours of solid, honest running yesterday.
Something which I makes me all the stronger, mentally and physically.

Just carry on.