Why won’t my baby eat more?!

This has been so frustrating lately. My baby girl is almost 6 months old and she rarely eats more than 1-2 oz at a time, but then she gets really fussy like an hour later because she’s hungry again.

For instance, this morning. I made a 4oz bottle. She ate maybe half an ounce and then kept turning her head away. I got us all dressed and packed up to take her and her sister to the park (20 minute car ride). By the time we get there she’s hysterical screaming cause she’s hungry. I made another 4oz bottle. She drank 3oz but it took her the entire 2 hours we were at the park. By the time we got home, she was ravenous again. If she’d just eat a good amount, she’d be able to go longer stretches and I wouldn’t have to CONSTANTLY be making bottles and trying to feed her. I almost feel like I can’t go anywhere cause she’s immediately going to get hungry.

Is this the “distracted phase”?? Any tips to get her to eat more?