I agree with a lot of the string suggestions above, but none are going to play good for a very long time. That is just the way poly is great for a while and then goes south quickly.
You say you are hitting 3-4 times with a hard swing, well if you got a week and a half out of hurricane then I would say that is about right. I never use a full poly job for more that a week or so, because not only does it play bad but the shock to the arm goes up the longer you use it.
I know that many players try to play with poly way longer than they should, but to be honest if you don't plan on changing strings often then you should not use poly.
I know that many cannot afford it and they will argue that this poly or that one will play good longer and it is okay to use it for a long time. And some do keep their playability longer than others but not by a huge amount.
My advise is for anyone that plays often and wants to use poly then buy a stringing machine and find a poly you like and purchase a spool and plan on restringing at least once a week. Not only will the fresher strings play better but they will not cause near the shock to your arm like the old stiff poly will.