Milk blister-- HELP!

I have an extremely painful, deep nipple bleb/milk blister that doesn't want to pop! I've applied moist heat before nursing/pumping (bathtub, shower, washcloth...), put olive and coconut oil on it, tried breaking the skin with a sterile needle and tweezers, scrubbed with a washcloth ... nothing is working and this thing has me in tears. I left a message for my OB, but she hasn't called me back yet. Is there anything else that maybe I haven't tried yet??