IM SO ITCHY

My skin literally feels like I've been rolling in grass all day. I'm 21 weeks pregnant and have already got myself a collection of stretch marks on my hips, thighs, bum, boobies and my belly. But my belly is so itchy I just can't stop scratching. Last night I scratched until I bled!! I use coconut oil, I've used Palmer's pregnancy cream, I've used macadamia oil I've used so many damn oils and creams ranging from high end to cheapies and NOTHING gets rid of the itchiness. Please. Someone bless me with a solution before I literally get the potato peeler out and start peeling off my skin. I feel like with every scratch I'm taking off a layer of sanity.