Please don't judge - pregnant with #2

Right this will sound crazy to some but I am having a melt down over having a second child. My first born who is now 5 is my world. Well he is more than that. I'm am so scared in case Its totally different with number 2 what if I love them both differently. Is this normal to worry about this. Everyone keeps telling me I'm being silly but I am petrified that I will love one more than the other and also leaving my boy out when the new baby arrives.