Breastfeeding problems

So I have a lump on my right nipple that was hurting extremely bad I went to the doctor to have it checked out and he told me not to feed of that breast for now until mid next week (after I finish my antibiotics) it's been a few days now and I feel like she's not getting enough from just my left breast. She eats for like an hour falls to sleep on my breast and as soon as I put her down she's crying looking for the boob again. My milk supply has also went down I went from pumping 2-3oz to now just getting 1oz from both breast I'm freaking out I don't know what to do.