What Causes Loss Of Motor Control Of The Limbs?

I have been experiencing loss of motor control of my legs and sometimes my arms. This started 6 years ago, but a year would go by without any incidence. During the past 2 years the episodes have occured more frequently. During the past 3 months the episodes have significantly increased and last longer in duration. I can't walk right because I can't control my legs and often fall. The loss of motor control sometimes leads to complete paralysis of my legs, where I can't move them at all. The duration lasts from 30 to 60 minutes now, where before it only lasted for up to 5 or 10 minutes at the most. I am afraid because of the increase in episodes and the increase in duration that this my lead to a permanent loss of my motor control.