I get numbness in the front part of my left thigh when i lay down, have also had eye twitching and severe back pain at times. what is it?

Varies: They may not all be related. The two most common causes of numbness in the thigh is a "pinched nerve" in the upper lumbar spine or a condition known as meralgia parastetica, in which a nerve known as the lateral femoral cutaneous nerve is irritated at the pelvis. Neither would typically becrelated to a twitching of the eye. Getting a good medical check up might be a good place to start.