YOU SAID:

these last few weeks have been exhausting

INTO JAPANESE

ここ数週間は疲れ果てています

BACK INTO ENGLISH

I'm exhausted for the past few weeks

INTO JAPANESE

私はここ数週間疲れきっています

BACK INTO ENGLISH

I have been exhausted for the last few weeks

INTO JAPANESE

私はここ数週間疲れきっています

BACK INTO ENGLISH

I have been exhausted for the last few weeks