Could you describe the feelings of nurabness? If you develop any bowel or bladder problems, you need to call your doctor immediately. This might be a sign of cauda equina and you need to be seen right away or you could end up with permanent damage and/or problems.
If the nurabness is like pins and needles, like when a lirab "falls asleep," it is OK to go about your activities as you can. If the leg is truly nurab and has no feeling, you will need to be careful as the danger of falling is high. You won't really be able to tell how you're putting your foot down, etc. You won't damage anything by exercising, etc., you just won't have very good balance, etc.
Diclofenac isn't really a pain killer. It is an anti-inflammatory and is prescribed commonly for arthritic pain, or to help keep inflammation down. So you should keep taking it. Your doc is hoping it will cause the inflammed tissue to go back down and thus, take pressure off of the nerve root.
In the meantime, do NO lifting, twisting and do not lean forward or especially, back as in extension. This will pinch the nerve even more. Try icing for 20 minutes at a time. Taking the diclofenac is probably the most important thing you can do. Activity level is less important. Lying down is better than sitting or standing though, as you can unload the discs (gravity....) If you can, you could try lying down about 10 minutes every hour. You're trying to give the area a chance to decompress and move off that nerve root.