Without pictures it is difficult to determine what exactly is going on, however itchiness is usually normal after surgery as it usually represents nerve endings healing. When they heal, they fire off randomly creating a sensation of itchiness, pins and needles, little electric shocks etc. Itchiness could also be a fungal infection but that's rare after a breast reduction. Best is to ask your surgeon and he/she can see you and best answer your concerns. If needed they can prescribe you some meds that might help
You need to give it more time for the scars to heal (at least 12months). The issue with the nipple being red and itchy is normal at one month. It would be best if you include photos of the nipple so we can see what you are referring to with "no nipple".
Dear Catlaw7, thank you for your question. I am sorry to hear that you are experiencing several problems following your breast reduction. Without a photo it is difficult to advice however, if you say that you do not have a nipple on the left side, I would advice you to go and see your surgeon. You might have suffered a partial or total nipple necrosis, a fat necrosis or a significant delayed healing. Contact his office and I am sure he will be happy to see you and assist you.
All the best with your healing.