I love my boyfriend and we are happy together. But when he's away from me, I don't care if he's happy or not. But I want to change

We've been together for 9 months. This is a strange one. Because I love him so much and when we're together I care if he's happy and we are really happy together. If he has a stressful day and we're not meeting I don't care about him. I don't care if he had fun on his work vacation a few weeks back, he sent me photos and I didn't even look at them. We text every day saying how much we miss eachother, but all I kept thinking is I want him with me.

I want him to tell me stories about his nights with friends and be genuinely happy he had so much fun, but when he does I don't care. We have a strong loving relationship and rarely argue.

Now when we're together, I want to make sure he's happy and always smiling. I want to be happy for him when i'm without him. What can I do? I feel like a monster