I'm breastfeeding and on my right breast there is a lump which just appeared now n it's paining what to do?

Sounds like a plugged milk duct. Make sure you empty that breast, and warm compresses are very helpful.

Make sure you feed baby all positions like football etc. I had the same thing but kept feeding and eventually went away. If it doesn't I hand expressed that part..it hurted some but I did it before and after feeding.