Hiya, I know how you feel. Bella is 11 weeks old and I had 2 weeks off with her when we had her, then went back to work when she was weeks old, but only til one oclock. My daughter comes home at half 12 and feeds her and then she is on her own. Next week I will be working til 3 so she has had a gradual adjustment. She is fine. I put her crate accros the utility room with the door open and she has room to play. When I come home she is so adorably happy to see me that its worth it. I take her out for a walk and then play in the garden with her. She is a bit more hyper than at the weekends when we are there, but other than that she is fine.
I try to put her in her crate even when I am home at weekends so she has a routine. Good luck he will be fine.