Whenever i lay on either side too long, that whole side goes numb. why is that?

Circulation: Similar to getting "pins and needles" when you sit on your legs in one position for too long, the circulation can be interrupted and lead to nerve irritation and numbness. It is important to periodically move around, even if simply repositioning yourself. Hope this helps.

Sciatica vs neck: We need to know if your whole body goes numb on that side - ie, from the neck down. Or is just one buttock and leg that gets pins and needles? The former could be a neck compression and you should get a neck spine MRI (esp with your med history). The latter is probably just a transient pinch of the sciatic nerve and is very common. A change in position takes the pinch away. Prob not a TIA.