First of all, its OK to feel so sad and cry, and if that bothers anyone else, too bad! You have had a terrible loss and need to do what you need to do, and not satisfy anybody else's ideas of what is appropriate.
As for the cousin, maybe you should let her/him know privately about your loss ahead of time so there are no inadvertant hurtful remarks made when you see each other. And if there are and they make you cry, go ahead, you don't have to come up with polite comments to make an insensitive boor feel good.
This Easter will be hard for you, but with your family's support and love you will get through it, and who knows? Next year may be better!
Wishing you many happier days ahead!