Formula to find and label duplicated (question bank)

[Musaab_R]

Hi

I've more than 10,000 questions and counting, and many questions added daily, the issue is finding and labeling then deleting the duplicate, duplicate are not exactly unique same question written with similar words but different context , and sometimes exactly the same but with extra word.

i used the 2 duplicate extensions and it is very useful but it need too much manual work (see attachment )

so my question, what Formula can i use to label any question in separate column and flag the question as duplicate and linking the duplicate form with lookup/rollup, so i could ? 

i wish the result to be like that .

thank you , i will really appreciate your answers.

[Musaab_R]

anyone ?