Seeking Advice

So I am super pregnant. With that comes pain, no energy, emotional, irritability. Last pregnancy I sat and watched Lost. I only did what I felt I could do. This pregnancy I am taking care of a terrible two year old. She makes me doubt that I will survive this last month. She makes me ponder whether I am the good mother I thought I was. She causes me to fear what things will be like after the baby is born and I haven't slept much. I just don't understand what I am doing wrong here? Why do I feel like I am approaching my execution?  There is nothing in the google search that can explain to me how to survive getting ready for and having a second child. So... did anyone else struggle the way I am or were you all blissfully excited for your new additon? How do you thrive during this time?