re: I said no to marriage with my cousin - and getting emotional blackmail…
^You should take that as your chance to dress in Tahitian apparel. He’ll be back to “English” in no time.
Okay, more seriously…have you even tried speaking directly with your cousin and his mom (your chachi)? If your own parents are not backing down…perhaps your cousin and his mother will end the rishta if you’re honest with them and explain that you don’t want to marry him at all and that you’re being pressured to do this. See, what happens.
Tell your parents that they have the choice to either end this as respectfully as possible…OR…they can take you to Pakistan where you will reject the rishta more openly and harshly (to get your point across) in front of all family members. Maybe the latter will scare them into ending this. They’re trying to blackmail you…shift the power over to your side. I’ve actually seen parents back down when they understand that their child might do something more drastic that could “mar” their good name and izzat in a bigger way.