20 month age gap - so scared

I just found out I’m pregnant with my second last night and my first is about to be a year. We weren’t trying but weren’t preventing (obviously) but now that it’s happened I feel so scared and guilty. My first baby is still SUCH a baby and needs me so much. And I feel guilty for feeling scared because so many people would love to be in my position and I feel like a terrible person. Just looking for some support