Hi Shauny,
This is the best that I know, and it's awful that you are in so much pain.
Here is what I know about your problem:
MRI scans are an extremely primitive method of diagnosis, and unfortunately, medical science does not have much better at the moment.
A number of treatments are often needed for back problems. From your description, there has been permanent damage to your back and so your problem is chronic, in other words, you have it for life. However, with the right maintenance, you can live a full life, relatively pain-free. This means:
Maintenace treatments from a good osteopath/chiropractor/cranio-sacral therapist, as Andrew suggested;
Getting a good personal trainer to show you how to strengthen your back, so that it can hold you up better and relieve the areas that have too much pressure on them;
Doing regular exercise as recommended by the good personal trainer;
You can also benefit from Pilates exrecise one-to-one at a reputable Pilates studio;
A massage once every two or three weeks can also help keep your back supple;
EFT (a mixture of acupressure and psychology) can help you with both the pain and with rehabilitation/speedier recovery;
Acupuncture can help with the pain and with your body condition;
No more rugby/moving heavy things - a small price to pay for a comfortable back.
If you live in London, you can PM me for a recommended list of all the above.