These are definitely signs of a clogged duct, which can turn into mastitis. The body aches are a sign that it is getting infected. Do you have a fever? You should let you doctor know. This has happened to me, but I have never had to go on antibiotics for it. In fact I was really sick and miserable once with it, but I was able to get over it myself without antibiotics. But I had a doctor who did not like to overprescribe antibiotics so he allowed me to wait a day before starting them.
I'm sure you have got some good advice on how to help this. You can use a heating pad on the painful spot. In the shower, use hot water on the spot and then with a comb massage from the top of the sore spot down towards the nipple (or up depending on which part it is in). When you nurse on that side (and you need to keep nursing on that side a lot) massage with your hand while the baby is nursing, it will hurt, but if you don't work out the clog, it will become infected and a problem. The main thing is to keep working at it. If the baby is not nursing enough to empty the breast you may want to pump as well and continue to massage it while pumping. Oh, and one other thing that would help is to change the position of the baby so her chin would be pointing towards the sore spot. Makes for some interesting positions, but sometimes that will help them drain that area more effectively.
I hope that helps. I know this is very painful and not much fun, so I hope it improves quickly. If it will not go away or you do get a fever, then you may need antibiotics as another poster said. Also, try to get some extra rest. I know that is easier said than done, but don't stress about housework right now, just rest whenever you can.