I've had it twice...First time it started at night and in the morning my breast was opainful and had few hard places, I went to GP and had antibiotics... But second time I had it wasn't that bad ( sounds like yours now). You need to go to docs unless your breast is getting red patches or you starting to have a fever. Otherwise it should go away in 24 hours. Make sure you keep your breasts warm, massage it gently and often, it's really good to massage while you in the warm shower or bath. And give that breast to baby as often as you can ( babies are the best in unblocking ducts)...Also rest a lot and drink plenty of fluids. Most likely it will not get back to normal till tomorrow if it started today. As I said before it usually takes 24 hours to see the difference.
Good luck!