Hi el tel,
obviously you've had lots of advice already, but for what its worth I had a similar issue to yourself about 7 years ago (I was 27 at the time).
One of my lower lumbar discs (I forget which one) prolapsed and had moved backwards and was putting pressure on my spine and sciatic nerve. From what you've described, very similar to what you are going through, only it was one disc for me, not two.
I was bed ridden for 3 months (not moving even to pee), and finally had a micro-discectomy to remove the contents of the disc that had leaked out. I didn't need to have any bone removed. For me it was amazing and I was able to walk (after a fashion) the following day. Obviously everyone is different, and there are always elements of risk, but I know I was glad to take this.
Yes, I needed recoupertaion, as I hadn't been using my legs for a while and they needed strengthening up. To cut a long story short - 6 months after the op I started snowboading lessons, and have now been 'boarding ever since. I'm not great, but I do jumps and go off piste while no back issues.
I also ride a KTM 950 Adv, and starting to ride off-road - again with no back issues.
However, as someone said, doing all these things are fine if your body is telling you its OK. Don't listen to people that tell you it can't be done, but do listen to your body - it doesn't 'normally' lie.
With your bike - get it set up to suit you, to make sure you're not putting your body under undue stress. I'm 6'4" and am getting 2" bar risers so that I'm not breaking my back when up on the pegs.
Aside from this there is no reason (op permitting) that you can't do all that you want to do.
Good luck dude.