Thanks in advance ^^
'I begrudge every moment that I feel compelled to rest. These intensely interesting subjects weary me far more to write them out than to speak upon them.'
It's hard to understand in bold letters.
"Weary" is verb here, I convert it to adjective.
I convert "far more" to "much more"
And I write:
"Writing these intensely interesting subjects is much more a weary activity to me than speaking upon them."
As you notice, that sentence is comparing two activities. If you want to know what "write out" and "speak upon" mean, look them up in a dictionary.