Thank you for your question. Botox has been successful in treating back spasms. A consultation with a physician would be required to determine if this particular treatment is right for you. I would suggest scheduling a visit with a doctor to discuss this option.
I am not aware of any issues that would arise with Botox injections due to pre-existing temporal arteritis. You should still get good cosmetic results with an experienced dermatologist.
I'm sorry you are unhappy with your Botox treatment. The effects of Botox typically last 3-4 months and tend to wear off gradually. You should return to your previous look over the coming weeks.