Pregnancies close together stories?

Agnes
We just found out last week we're expecting again, I'm about 4-5 weeks along...our beautiful little girl was born in Jan 2016 so they'll be almost exactly a year apart!! I admit this was sort of planned, we didn't want a big age difference so decided to start trying as you never know how long it'll take. My first pregnancy and labor was basically textbook, no problems despite pre-existing blood pressure and weight concerns and I seriously felt totally normal within a few days of giving birth. My gynecologist gave us the go ahead to start trying whenever we wanted at my 6 week appointment - although she recommended waiting until the first one was sleeping through the night :)
However, I can't stop worrying about miscarriage (no history) or this second baby not getting everything s/he needs because of my body still being depleted of nutrients from the first pregnancy. Anyone want to share their stories of what a pregnancy so soon post partum was like?  I need reassurance that I'm not seriously risking my health or that of the baby?