There are many reasons for a dog to lose hair: hormone imbalances like hypothyroidism and Cushing's disease; a skin condition called Alopecia X (what my dog has); skin infections and allergies and autoimmune diseases. The treatment is different, depending on what she has.
I would start with blood tests to see if she is low thyroid or has Cushing's. If so, treating with thyroid supplement or treating the Cushing's should restore her hair. If the blood tests are normal (like they were for my dog), a skin biopsy should tell you why she is losing her hair.
My dog has a fairly rare condition called Alopecia X. Most dog with this condition regrow hair if given melatonin, a hormone supplement available over the counter. It did not work for my dog, however. The next thing I tried is a supplement called flax seed oil with lignans (the key is the lignans) and within a month I could see new hair growing, and now 6 months later she has all her hair back!
You could try melatonin or flax seed oil with lignans; they are both available over the counter, but they won't help if she is hypothryoid, or has autoimmune disease, so I would have some blood tests done first.
The growths on her back could be benign or could be cancer. Since they are black, they could be melanomas. The only way to tell is to have a fine needle biopsy done in your vet's office, or to have them removed and biopsied.
Let me know if this helps, and what else I can answer or help with. I am sorry I can't do a phone call, but I really liked your question since my own beautiful dog was going bald and I wanted to let you know there is hope!