The hormones after having a baby will wreck havoc with your moods and separately SO DOES LACK OF SLEEP. If you have trouble sleeping with the help, you can even ask the doctor for sleeping pills. The goal of the help is to make your life more regular and scheduled, so you can assume some sort of normal routine (eating, sleeping, meals, laundry, shopping, etc.) Anticipating this will help motivate you to accept the help and as the others suggested help from organizations make be comfortable to take.
You make be able to give over shopping or laundry duties to a friend.
Despite your exhausion, try to see what you need, what type of help and when, and you will be able to get your life somewhat under control.