please suggest what to do..

You have mentioned your age as 78 in your profile. Correct it, if it is wrong. Regarding the question at hand, you love your cousin and I take it for granted that you are a Hindu. In certain Hindu communities, you are allowed to marry cousins, who are from different paternal lineage. That is you can marry your maternal uncle's daughter or paternal aunt's daughter. Consanguineous marriage has a n increased risk for some autosomal recessive diseases. If you have taken everything into consideration, go ahead and marry the one you love. I know quite a few people who have had Consanguineous marriage and are happy with what they have done. Its your choice.

if u belong to hindu family then it is really difficult and even if you get married your social acceptance will be veru low

I think cousin should not encounter, if you have offsprings, high chances that you will have genetically defect babies, either heart defect or mentally retarded. That's the reason behind why we could marry with direct family member or close relative. Cruel to say, it would be wise to stop this relationship. I still it's ok if you promise not to have a kid in the future. Be responsible, you won't want to have a mentally or physically defect child.

I'm afraid there is no way unless change the law. I don't know the law in India, but I think it must be against the law for someone getting married with his/her cousin. You got make a decision, the sooner the better.