I did 3 injections and always felt A LOT worse for a couple of weeks and then back to my regular severe pain. My chiropractor told me they only tend to work for about 20% of people. Because of the risks associated with them, and the fact that they brought me no relief at all, and would never do one again.
Surgery shouldn't be considered until all conservative treatments have been tried and failed. Have you tried PT or anti inflammatory medications?
The reason they don't just jump into surgery is because is because back surgeries are very big, and painful procedures. It takes forever to recover from them (up to a year), and they don't always even work. I had a fusion 9 months ago and it failed. I am now having another fusion, but this time 2 levels will be fused instead of one. I am with a different surgeon this time so I am crossing my fingers for a better result.