You had a procedure called an IDETT or intradiscal electrothermal therapy. It was based upon the principle that heating collagen will “melt” it and cause scar tissue to form. This procedure was hoped to stabilize the disc wall and disrupt the pain fibers (nociceptors) in the wall of the disc.
Unfortunately, IDETT did not work as planned. Heat generated from this device also could cause thermal damage of other nearby structures and this might be why you developed foot drop in the opposite sided nerve.
The discogram did identify your pain generator but the IDETT unfortunately was ineffective.
I cannot comment on the use of your pain medications and muscle relaxants.
Steroid injections can mimic what surgery has the potential to do but remember that these medications are anti-inflammatories. Inflammation is generally the cause of pain (along with nerve damage). The injection might very well forecast a surgical result but it is not a 100% correlation.
Injections are also not foolproof. The volume of the injection can cause a pressure phenomenon that aggravates symptoms and rarely, the fluid can be injected into the incorrect area which can also cause new symptoms.