First of all, you should get the experience with the chiropractor out of your head. It's not uncommon for chiros to argue against surgery and continue to have you seek their treatment for years on end.
Second, being scared of any kind of elective surgery is normal and completely understandable.
Good idea to google on the spondy and learn as much as you can.
third, seek more than one opinion from spinal surgeons, both orthopedic and neurosurgeons and be sure that they are spinal specialists and specialize in spines only.
You want to use a spine specialist that does only spines and not other orthopedic issues as well.
Get all your questions answered from your present spine specialist. things like
What type of surgery is he saying you should have.
How will it be done
what will the end results give you.
what will recovery be like
How long to recover
etc.
Then get copies of all your records and tests that where done to diagnose you and seek out several other opinions.
There is more than one way to do a fusion and the more information you have, the more opinions and how different spinal surgeons would approach surgery for you can be enough for you to change spine surgeons, give you the answers you will need to make your decision. etc.
In the end, only you can make the decision to either have or not have spinal surgery. But, the more information you have, the more you understand and the more opinions you have, will make that decision easier for you.
You fear my just be normal fear of surgery and it may be that you do not have enough confidence in the spine surgeon you are using.
By getting more opinions, you will be able to determine what is making you unsure of what to do.
Good luck and keep us posted on what you decide, what the other opinions are and what you are thinking.
Fran