I have really bad strech marks, coco butter and lotion made for it has done nothing. What can I use to get rid of them?

They fade, but stay. Pregnancy stretch marks, as well as stretch marks from body building or obesity, are lines where the second layer of skin (the dermis, under the surface) has cracked and separated. The stretch marks heal in that position, but their width narrows after the tummy shrinks down after delivery. The lines fade with time, but never go away completely. One can ask a dermatologist for an evaluation.