Twin Flat Spots!

I thought my DH and I did everything we could to avoid this but both of our two month old twins are getting a flat spot at the back of their heads!!! Every time they are in their rock and play sleepers or cribs they both prefer to stay with their heads up- we try to gently turn their heads to the side but they turn them right back. Their pediatrician said they aren't anywhere near needing helmets but omg! How do I prevent that??? She said all I can do is more Tummy time which is crazy hard since I'm a SAHM of two newborns and get NO help. I thought as a FTM and having two babies that I was doing ok but right now I'm feeling like a failure.😭