First off I have to say I sure know what you must be going through. Don't give up on riding, but be careful.
I herniated two lumbar disks back in the 1980's. I was unable to walk for awhile due to severe pain and pain in my leg, but I opted to not undergo surgery. Gradually, over time, and with a home health nurse, I did get better and was able to walk again, altho I can't walk very far or for very long. Fast forward to the present day; the disks are now gone (they deteriorated basically) and it is basically bone-on-bone, with a few other issues as well now. I'm real careful what I do, and still have no plans to have surgery (a multi-level fusion would be needed, and I hope to avoid that), unless it gets to the point where the spinal cord is at risk of becoming compressed, so far it is not looking as if that is the case, yet. There were times I wasn't able to ride much or at all, and when I did ride I pretty much just walked my horse, or when I did trot I made sure I always posted to the trot.
One thing I noticed, and so many people found this hard to believe, but for me horse back riding was no where near as painful as riding in a car. For me, riding helped my joints and muscles to be less painful, as long as I kept my feet directly underneath me, like you do when you ride a horse, I did pretty good as long as I didn't overdo it. Also, now that I am older and my back is a bit more messed up due to the passing of time, if I should ever get another horse (I'm horseless right now) I am seriously thinking of a gaited breed.
Hang in there, and never give up!
ETA: I wanted to add, cycling has also helped me too, I had to make sure I bought a bike that allowed me to sit more upright though. And, as for chiropractors... I know everyone is different... but for me and my disk issues, I cannot, and will not ever again, let a chiropractor touch my back, it's just too much of an aggressive form of treatment for my spine. Altho some people have had luck with it, I would be very careful there.