Sounds like you need the operation.
From a work accident I had L4/5 disc excision, then a year later L4/5 fusion. This was in my 50s.
In those days they went thru the back and now I have no muscles in my lumbar spine as a result of the 3 operations. Muscles slowely died.
I had another L2/3 fusion (mimimal invasive through the front) 3 years ago.
Also have major arthritis in the lumbar region.
I had a Spinal Chord Stimulator for 8 years that cut down the pain level and probably getting another one in February.
So in saying all that, I think that these days they try not to take the laminar bone out during operations, to minimise adjacant spinal levels failing.
For me it's been about 30 years of reasonable good health, that I would not have had had it not been for the operations, so I think if you are older you may die before the other spinal levels cause a big problem.
Sometimes it's better to have the operation rather to be in constant pain and stress.
I think you can take Celebtex (anti inflamatory) for a long time, but just need to make sure your stomach doesn't get too many ulcers.
My only advice is to find the best surgeon you can (if you decide to have the op).
@Sheryl seems to have a list of the best surgeons in Bangkok.