Twins help

I have 2-month old twins and at our 6 week check-up our Dr stated that one baby has been looking to the right too much and needs to look left more. His head is a misshapen(flat spot) from looking right and belly time should help with that.

I feel HORRIBLE about my sons head and it eats at me so much! The problem is, is his sister is fussy sometimes and more clingy so she gets more attention. My son is much calmer and easy to soothe. I have been trying my hardest to give him more attention. When he does lay down I try

To turn his head or encourage him to turn his head to the left but he always turns it right again. When I do belly time I can tell he can’t lift his head up as good as his sister and he screams like bloody murder. My husband and I feel so bad!

Idk what to do, his head is still misshapen and I feel terrible that he can’t hardly lift it off the ground. Every time I go to hold him, his sister starts crying. She just likes to be held. Does anyone have any tips?