I was reading an article and think it makes some very valid points. Here is a link to it if you want to look it up but it basically says that a baby is helpless and "totally dependent on others for his needs. During this stage, the infant learns whether the world in which he lives can be trusted. When he is hungry and he cries, will he be fed? When his bottoms are wet, will his diapers be changed? When he is unwell or afraid, will he be comforted?"
http://www.vtaide.com/blessing/ERIK1.htm
I agree with this article on a lot of points. Giving in to the demands of an older child is not good for them but when a baby needs something they just have to cry until the need is met. So meet that need. As the child grows safe and secure in his world he will learn to be independent. I don't think I can recall seeing any moms walking around carrying toddlers because they didn't want to get down and explore.
You will do fine. If it gets to be too much have someone help you out by watching the baby all night and let you sleep. They can wake you up if there is an emergency. You can't give good care if you are exhausted.