I feel like a horrible mother???

My baby girl has a neurology check up tomorrow. My husband has had that day scheduled off at work for months. Well they tell him today all the time off request are denied until further notice. Because they are short handed. So that leaves me not being able to take her to her appointment on top of having to miss baby brother's 2 month well child check and his surgical check up. If this holds out until July. I've called all my family and no one can really help. I'm not my dad step kid so I'm not a priority. My sisters on vacation. And my mom just started a new job. So that leaves me no way to get them where they need to go. I've never felt this bad for not being able to drive before.