Walking in cloudy with a chance of meatball

I keep asking myself if I can do this.  Can I handle another newborn while juggling a toddler?  I know I can and will.  I think I'm really asking myself why am I doing this?  The exhaustion, the sleep deprivation, the giving of oneself completely and totally to this is tiring just to think about.
Now I know it's a rhetorical question.
Allow this pregnant woman to panic a bit but not to the point it becomes worrisome.  Worrying is one of the worst things a woman can do during pregnancy or at any time for that matter.
I guess I'm just feeling the effects of this pregnancy more physically this go around and hence, I'm thinking about the months ahead.
See the first go around, you are unaware of the actual labor and toll a newborn has on your mind and body.  So you walk in completely in bliss and ignorance.
Subsequent go arounds, you are just willingly walking into it and since it's the second go around, you probably have a young child in tow which lowers your peak performance levels already.
Essentially, I'm walking into newborn motherhood not feeling at the peak of my performance level and I'm willingly doing so.
Talk about being a glutton for punishment.