I know it's very hard for you to see your wife not feeling well, but know that what she's going through is completely normal. Her hormones are going crazy right now, and she's exhausted, but before you know it, she'll be over the morning sickness and she'll be feeling a lot more energetic. The baby is running the show right now, but things will settle down in a few weeks or so.
You two will be wonderful parents! You're both smart, sensitive people and you'll figure it all out. I know it all seems pretty daunting, but you'll be ok. I can't wait to be a gramma!
Take it all one step at a time, and ask for help any time.