Is it okay to marry your cousin?

it's perfectly okay to marry anyone, even your sibling. The concept of incest is from an age where there was no contraceptives. Nobody bothered to review the concept after the advent of contraceptives. And going by the concept of incest, there are as many babies suffering from outbreeding depression, like how it was during inbreeding depression.

But what you need to do first is ask yourself
What is Marriage and what are you trying to acheive by it ?