The age difference between #1 and #2 was 12yrs so i didn't have that much of a problem but the age difference #2 and #3 is about the same one you'll have between your two children.
At first it was overwhelming because we hadn't settled into a pattern and schedule, but after a few weeks, it started to get easier. My son (#2) was still in diapers and needed my attention a lot. He wasn't a big fan of the new baby with her constant crying and taking my attention, but he liked to help me with her (handing me diapers and throwing things away). I made sure though that each day I he interacted with the baby and I had some alone time with him. I think the hardest part was trying to potty train him and getting him to sleep in the toddler bed since we gave the crib to the baby.
Every family is different: some get really stressed out, others handle it better. But think about this: if this task really was extremely difficult and a huge stress factor, would there be as many people as there are today with 2+ children? You'll adjust just as you did when you had your daughter, and personally, I think going from a couple to 1 child is harder than going from 1 kid to 2.
I wish you the best of luck and congrats!
