All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
We advise him to marry his cousin if he can do so, especially that she waited for him for four years. This is evidence that she still wants him and loves him. However, if he does no longer want to continue because he does not like her, then it would be better for him and for her not to marry, as the marriage that takes place without the will of both parties is generally doomed to fail. Allaah Says (what means): {But if they separate (by divorce), Allaah will provide abundance for every one of them from His Bounty. And Allaah is Ever All-Sufficient for His creatures' need, All-Wise.}[Quran 4:130].
Allaah Knows best.