low back or backless style for wedding

I am 47, and had a hip replacement in January 2017.
I had a horrible time, getting infection, was so sick.
Now I have arthritis in my spine and SI joints. The pain is starting to get severe. The only way I can explain it , is it's like really bad menstrual cramps in my lower back. It's terrible and drags me right down and makes me so tired, but even worse, I am completely terrified. low back or backless style for wedding
I'm so scared I am going to have to live with worsening pain and finally end up totally crippled or bedridden. I could not live like that. I would not go on.
What are my options? What treatments are available for your spine and SI joints? Am I doomed?
Please help.