Hi crazycrow!
Having neurological deficits (numbness and weakness), persisting after conservative treatment for a long time, means that surgery might be necessary to decompress neural tissue.
Nerves are very sensitive tissues and to be specific they are 'blood thirsty'. They need blood to function and when blood flow is disrupted, symptoms appear immediately. Numbness of the big toe is a neurological sign, meaning that the nerve's blood flow is disrupted anywhere in its route from the low back to the toe. You also have muscle weakness, meaning that you have motor disruption as well. Unless the cause of nerve compression is treated successfully, the nerve won't recover by its own. If conservative treatment fails to eliminate symptoms, then surgery might be needed. It must be said that one has to be certain that the area of nerve compression is at the low back, where the surgery will be held. For example, having a spondylodesis at the L4-L5 level when the nerve is not compressed there but somewhere else (e.g. at the gluteus - random example), then the problem won't be solved. That's why some surgeries fail. It's because the low back was not the cause despite a disc herniation.
What you should do immediately is to visit an MD again to have you examined, make suggestions on ways of treatment and then visit your physios to have them assess you again. Doing any sport won't make any difference, either positive or negative. What you have is very serious because the nerve might never recover if you do nothing. The nerve is compressed and decompression must be done ASAP.
Looking forward to hearing from you when you have any news.
ilias