Help! Engorged breasts.

Natosha • 💙J2015 💜N2019
Ok so I started out breast feeding but it wasn't working out for us so I decided to switch to formula ( please don't try to convince me to go back, I think BF is better but this is the right decision for us). 
So here's the question, what all can I do for some relief??? My boobs are so freaking engorged they feel like they're going to explode. I've tried icing them, heat, I just started using cabbage leaves yesterday. As far as the cabbage goes, how long does it typically take to really really help. It helps a bit but not too much at this point.