Now the solution to remaining able to work longer is going to be found through dissecting what you do each day both in the workplace and at home. Note down your observations and tackling them head on see what you can replace with an easier methodology.
I can promise you with great confidence that this does work, we ran such a scheme in my old factory and it made us far more efficient than before. I always recommend it for those who are already disabled and at home as a way of reducing their daily pain burden. I therefore think it is essential for anybody who needs to remain employed.
You can start to tackle the pain head first by examining your daily work routines and your daily chores at home with an eye to identifying and then reducing those movements and/or actions which generate pain for you. I have gone through everything I do step by step, examined those steps which generate pain and planned them out of the task.
So it sounds like madness when written down, in a kind of, "How do I get that out of the fridge without bending?", sort of fashion. But it can be a process which will almost banish pain causing actions, in some instances.
As an example of how it works at home. With Jude at college, I do a lot of household stuff and carried out such evaluations almost automatically. It certainly helped.
Furniture got moved around until it was positioned in such a way that I did not have to move it when hoovering, where it did have to be moved we fitted wheels or those moving coasters on the bottom. Now I can simply shove them out of the way.
Another example. The hoover we had was a dead duck and needed a lot of physical input from the operator to get the job done, so we went out and got a new one which was an instant improvement. We also moved the position the machine was left it because it meant having to lift it up a couple of steps. Obviously we are all different and your specific situation might not mirror my own or you will not have the financial resources to purchase new devices. However, if you don't try it, you will never know if it works or not. Feedback to me please.
If you are still working this next paragraph will only work if you have a sympathetic employer, remembering that the process can be applied to any job and that includes sitting down and typing all day! That too has it's trigger areas.
It would be my instinct to tell my employers about my situation and that I want to continue working. If your employer reacts positively then he or she will be as concerned about your safety in the workplace as you are. I don't know about your state regulations but in the UK employers who take on disabled people, or who keep them on after finding out they have a disability, can claim some money back from the state. So if an incentive is required you could find out about such schemes before you air the problem with that in mind.
The main advantage for employers is that these analytical exercises also have the spin off benefit of making many other tasks more streamlined, easier to complete and, as you are not in pain carrying them out then he is assured of your full attention to the job. A negative reaction could indicate that he is not the boss you want to work for. But that is up to you to decide, I don't even know what you do.