Thanks for that information.
Ideally, this dog needs to seek veterinary treatment. Her reluctance to walk or stand makes me think she has broken bones. The buckshot could have easily penetrated or chipped off pieces of bone. She also really needs some anti-inflammatories and pain medication.
Duramycin is not an antibiotic normally used in dogs, it is used in large animals. I would not give it to her.
For at home care I would take some electric clippers if you have them and clip the hair off the wounds. Then use Betadine mixed with warm water and gently clean the wounds with some clean gauze. Make circular motions for about 10 seconds each piece of gauze, then throw that piece away and use another clean piece. Then rinse the area with some sterile saline. Pat dry with more clean gauze and apply triple antibiotic ointment to the wounds.
You can put a light bandage on the area, do NOT use a lot of pressure. Just a very light bandage covering the wounds. Keep her in a warm and dry area.
If her condition starts to worsen you will have no choice but to seek medical attention. Please be mindful of her level of pain. I know that money is a concern, but unfortunately her wounds may be too severe to heal on their own.
Good luck with her, I hope she gets better soon.