I travelled on a visit visa to the USA but then have been rejected 5 times

I was first denied the B1/B2 visa. On my second attempt, I was given the visa for 3 months with an annotation “CPA EXAM – Maryland.” I took the exam and, out of two parts, I passed one part. But, in the same interview, the officer had told me you have to attempt all four parts and I am giving you one chance.

I returned within the stipulated time. Since then, I have reapplied five more times for a visa (on average once a month) and I have not been given the visa.

One more thing: after coming back, I told the officer that I would like to stay for 5 months as I want to pass my remaining exams during the stay. Also, the officer misunderstood my results and he recorded as if I had failed the two parts.

In my last interrview, the visa officer told me to “try to change your circustances and apply after a long time.

What should I do?