It sounds a lot like you had what is known as a vagal reaction. This often occurs in the scenario your are describing. Basically what happens is that internal stimulation of the body's organs during the act of using the bathroom triggers overactivity of the vagal nerve, which controls things like heart rate and blood pressure. The result is that blood pools in the legs, and the heart rate slows and the blood pressure drops briefly. This is enough to trigger a whole range of strange symptoms, such as numbness
or inability to speak as you experienced, also sweating, palpitations, dizziness
, and sometimes passing out. A vagal reaction is generally benign although if they occur frequently you may need to discuss them with your doctor
I think in this case it is worth talking to your doctor regardless. This is because there are other more serious things other than a vagal reaction that could cause similar symptoms, such as a disturbance in the rhythm of your heart or a stroke. These may or may not be likely in your case, depending on your age and your medical history or risk factors. Your doctor will be able to help you determine if further workup is needed.