YOU SAID:

I've lost any and all motivation to do homework today.

INTO JAPANESE

今日は宿題をするモチベーションを失ってしまった。

BACK INTO ENGLISH

I lost the motivation to do my homework today.

INTO JAPANESE

今日は宿題をする気持ちがなくなった。

BACK INTO ENGLISH

I don't feel like doing my homework today.

INTO JAPANESE

今日は宿題をする気がしない。

BACK INTO ENGLISH

I don't feel like doing my homework today.