Having arm, leg, and back numbness could mean you are having a stroke. A large determinant is whether one side of the body is affected, or the whole body. If the numbness is contained to one side, this could certainly mean you are having a stroke - in this case, most likely a small stroke in a part of the brain called the "thalamus".

However, if the numbness is on both sides of the body, it is very unlikely to be a stroke. A spinal cord lesion or a peripheral nerve problem are more likely.

It sounds like you should see a neurologist, and soon. Determining which of these scenarios is at work is critically important in trying to fix the situation before it could get worse.