Sorry bro's, stretch marks don't and won't go away.... ever. Unless you get expensive, not worth it, laser surgery. Chalk it up to genetics. I get a stretch mark if a girl bites my ass to hard and pulls. Some people will gain 200 lbs and not get one. They are red when they are new, white when they are old. I've had some for over 8 years now. They don't go away, get smaller, or anything. Tanning doesn't help, Vit-e doesn't help, all the miracle solutions don't help, nothing helps. The stretch mark actually accurs under the skin when your tissue grows faster than the skin can keep up with. Its kinda like a peice of plastic. When you bend it, it loses its original texture at the point of bending. When you bend it back, it's still white with stress at the point that was bent. You can't get it back to normal without melting the whole thing and then reshaping it (laser surgery)..
sorry to break the bad news.