In answer to you question, only the bods at LGW will be able to say. There are however, many hundreds of pilots flying with chronic back pain. With the advances being made now, it is perhaps more important to set your sights on a cure, rather than working round the pain.
IMO, taking drugs for pain while flying, is not an option.
It might be that treating your back like glass is the last thing that you should be doing. However, you must be guided by no lesser person than the surgeon on this point. My unqualified opinion is simply food for thought.
So much revolves around, not only the original reason for surgery, but exactly what was done.
In many cases, keeping the back strong is of paramount importance, but if the surgery was difficult--in terms of access to the target point--then some structural members, processes, may have been removed, and keeping muscles strong following such procedures then becomes secondary to keeping the remaining structure safe.
It sounds as though you were lucky enough to have a minimally invasive procedure, but there are almost always ongoing problems to cope with. In the case of operating through a small opening, the advantages have to be offset against not being able to look around at adjacent areas so readily. So, there may have always been another problem. However, it is likely that your residual pain is due to a reaction to the surgery. A neurovascular invasion of the disc material, is it seems, quite common.
To repair areas that don't have a blood supply means that such a system has to be created. This can't happen without an associated nervous system. I think I described such nerve pathways as a double edged sward. It is thought that pain travels back on these new routings. This is all quite normal, but a burden that may have to be borne–at least for a while.
It is totally unqualified opinion when I say that it may be possible to beat the system by exercise. Breaking through the pain barrier with greater and greater workload which will not only strengthen the structure, but may also tear away the (hopefully temporary) pathways.
I have no data on the natural reduction of such newly created nerves, and THERE IS NO WAY TO KNOW IF THIS IS APPROPRIATE, so you can only make slow inroads towards a goal of strength and the breaking of this neural pathway by exercise. No sudden increase of pain or sensations in the leg(s) is acceptable, and of course no sudden major spasm of back muscles. A very, very steady increase in angles and loads. Remember, professional advice comes way ahead of anything I say.
At your age the nucellus of the disc with be losing its resilience anyway, and the damaged fibers of the annulus fibrosus may simply be teasing at the outer of the spinal cord sheaths. There may be almost no problem at all--except for the spasm caused by the irritation.
The frustrating thing is, that in thousands of cases, there is almost nothing seriously wrong. A disc that has been altered, or that has subsided with age, may provide typically 1-3mm less disc space. This has the affect of altering the angle and range of the facet joints, and may compromise the neural elements, this in itself may be the cause of pain.
Long periods sitting are very counter productive when the annulus has been compromised. An increase of internal pressure of around 40% is typical.
I am convinced that in many cases, the way ahead is to keep strong.