How to say "think to say"

I have to translate the sentence " Although I was thinking that I'd say today that I would quit school, I failed to say that" (yeah I know its an awkward sentence)

I put 今日学校をやめると言い考えていたのに、言いそこなった。

My main question is: does "言い考える”　make sense, and roughly translate to "think to say"? Or does this form not work in this scenario? If it doesn't, what would be a better way to translate it？

今日学校をやめると言い考えていたのに、言いそこなった。
Instead say,
今日学校をやめると言おうと思っていたのに、言いそこなった。