what should i do?
Apply for ESTA, disclosing your other citizenship and prior visa refusals when asked.
You have nothing to lose but $4 (the $10 portion of the fee is charged only for successful applications, for a total of $14; a refusal costs only $4).
This is because we know nothing about the reasons for your previous visa refusals. If they came about because of some technical problems in your applications, for example, then the ESTA might well be granted. On the other hand, if we knew that you had been found permanently inadmissible for some reason, then an ESTA application would be a waste of time. But we don't know anything like that, and the cost of trying is rather low at $4 plus a few minutes of your time.
[What if the ESTA is refused?]
Then apply for a B visa. Consider coming back here to see whether we can shed any more light on your past refusals. This might help you submit a successful application. Or, if you can afford it, consult with a reputable US immigration lawyer.