Clogged ducts.. Any tricks out there?

So last night my breast got rock hard and I can't get any milk out of it by pumping, hand expressing or nursing..  My LO is 9 weeks, we have no problems with latching, basically nothing until last night. I know I have to nurse from the breast as much as I can, but because there is nothing coming out, my LO either uses me as a pacifier or gets upset and pulls very hard and my nipple is killing me now.. I'm trying to massage it and used hot compress but nothing helps and it's getting very painful.. I've heard about cabbage leaves, how do you use them? Anything else that would help? Thanks...