Have you got an electric toothbrush? Warm shower, massage the area using the toothbrush. Small movements, firmly without causing pain (but not just brushing your skin lol), going from behind the lump down over the lump towards the nipple. Circular motions.

Rest. Lots of. Fluids. Lots of. Anti inflammatories.

And massive sympathies.
If you don't have an electric toothbrush, I've cleared blockages with another useful vibrating device, if you have one of those. Hilarious, but it really does work (as does the toothbrush). Xx