Too two many doubts

OK this is going to sound awful but I want to be honest and I feel like you guys hopefully will understand. I’m having very mixed feelings about having another baby. My son will be two on Halloween and I’m pregnant with baby number two. I was so excited about it when I found out, now I feel nothing but doubt. How will I ever love this baby is much is I love my son? I never want my son to feel like he wasn’t enough. I am also the only child so I don’t understand what it’s like to have a sibling; how will I raise them. My son is my world is there room for this baby in our world?!