Am I missing something? "I would consider myself..." is grammatically correct, and the contraction "I'd" fits. The "affluent" gaffe is indefensible, though.
At the risk of prolonging all of this, which most people don't care about, I'll answer you. It's a bit more subtle than many here can or will grasp, though.
The sentence in question:
"I'd consider myself fairly affluent in English (look, I even used a big word!

), but I honestly hate being bored."
Grammatically, he is saying he'd consider himself fluent EXCEPT for the fact that he hates being bored. This is NONSENSE, grammatically.
Whether or not he hates being bored has NO bearing on whether he
considers himself fluent in English. See?
He considers himself fluent in English no matter what!
He may not
write or speak fluently at any one time
because he "hates being bored" BUT he
always considers himself fluent in English. This is his unvarying opinion of himself.
This highly favorable self-evaluation is NOT dependent or
conditional on
anything, let alone what is stated in the other clause in his sentence; therefore it was grammatically incorrect of him to use the conditional tense "would", even as a contraction.
Suffice it to say, the guy is not close to being fluent in English, despite whatever his Mother and all his lazy-assed teachers may have told him.