something is off?

Lauren • My husband and I have two girls, a 6 year old and 2 year old! We`re pregnant with girl #3 💝💝💝
So I just feel like my husband and I have lost that "spark". We'll be married for a year next month, been together for 8 years in august and I could feel how much he used to love me. I felt like he REALLY cared about me and there was no wrong I could do in his eyes. Lately everything I say bothers him, he's been drinking a lot, he always apologizes for things later on (like if he started an argument he felt was unnecessary). But, I can't help feeling in my gut something is wrong. He keeps saying he loves me, and cares about me...I'm just not sure why I feel this way? I love him, he was my high school sweetheart and father of my (almost) 3 children. (Due with #3 in august) I'm worried it's because he thinks this baby (which will be our last one) is a girl and he'll never get our boy..he's wanted to be a dad to a little boy his whole life. (He doesn't have the best relationship with his dad so he wants to make that up to his son). I can't change anything..this baby is whatever it is going to be. I feel like if we find out this baby is definitely a girl, things won't ever be the same and it makes me so sad. Sad for him because I know how badly he's wanted this relationship, and sad for me because he'll always wonder. part of me is not sure if he'll ever really get over it..?
What do I do? I love this man with my whole heart and never want to give up on him, but I don't know how to help him see everything he has already!