Shallow latch help

Any help or advice for a shallow latch?

I've tried everything, pulling chin down, different positions, sandwich technique, shes been assessed and treated for ties and it hasn't regrown so it's not that. She doesn't tip her head back like she should no matter what position or where I support her, she's almost 7 weeks old now and although it's no longer painful my nipples are still pinched or lipstick shaped every time and her lips have a permanent blister from the shallow latch.