Ttc #2, but I have days that I am not broody... At all

So my 3yo is acting spycho the past week. So moany, everything sets him off, stubborn, needy... So a perfectly normal 3yo. Love this child to bits but gosh today was trying. My SO and I decided to start trying for #2, and last week i was so excited...but today, I am dreading falling pregnant. We are so comfortable now, we have started to really enjoy life again and being more active with our son, and he requires so much energy which we give willingly. But if I fall pregnant, I won't have the energy. So other mommies who have a second child, I know it's not easy, but is it as hard as I fear it is going to be?

I have days where I am broody and excited, and know I can do it, then days like today where I can't actually fathom doing it....