What should I do about the debt I owe my cousin for three years, given that I have no financial means to repay it, and I fear dying before settling the debt?

It is prescribed for the debtor to frequently recite the Prophet's supplication (peace be upon him) before sleeping: "O Allah, Lord of the heavens and Lord of the earth and Lord of the Great Throne, our Lord and the Lord of everything, Splitter of the seed and the date stone, and Revealer of the Torah, the Injil, and the Furqan, I seek refuge in You from the evil of everything You hold by its forelock. O Allah, You are the First, so there is nothing before You; You are the Last, so there is nothing after You; You are the Manifest, so there is nothing above You; and You are the Intimate, so there is nothing beyond You. Settle our debts and enrich us from poverty," and to have a good expectation of Allah, for the Prophet (peace be upon him) said: "I am as My servant thinks of Me."

Moreover, the creditor must grant a respite to the one in hardship, as Allah Almighty says: "And if there is one in hardship, then [let there be] a delay until [a time of] ease." And glad tidings are given to whoever intends to repay a debt that Allah will repay it on their behalf.