Is it just me...

My son is 6 and my whole life literally. I just started datining again in June and this relationship is moving fast. We're engaged to be married and expecting a child in July. But my thing is this....I don't know that I'll be able to love the new baby the way I love my son. I love him so unconditionally and fully and he's beyond spoiled snd I'm terrified that I won't be able to spread that equally. What do I do? Any advice will be well revived.