Is it possible to cause damage my nose by yelling and crying 4 days post op Rhinoplasty?

Don't stress too much as you have not caused any permanent damage to your nose.  Activities that increase your blood pressure (like sreaming) can temporarily cause swelling and bleeding of your nose, but will not impact your final result.  

I don't think you have anything to worry about but check with your plastic surgeon anyway. Four days after rhinoplasty the nose is remarkably stable.

It is very unlikely that the nose can be damaged simply from yelling four days after surgery.  If anything the swelling may worsen from an increase in blood pressure.  It is best to sleep with your head slightly elevated with about 3 pillows and to avoid strenuous physical activity to help decrease the swelling.