Now that I'm a Mom, I can tell you that it does zap you of energy, but you find it worth it somehow. Does that mean that you always like being woken up randomly when you are in a deep sleep? No, but it's a privilege in the end. I mean, if you are like me, I didn't GET to become a mother until later in life, and since the first child, I have not had the privilege of conceiving a second. Many women are wishing to have even their first. All that to say, I don't look at the gift of a child as a small thing, whatever our age, and the "inconveniences" are so worth it. My son still wakes me up occasionally (and he is no longer a baby or even a toddler). I find myself having to get the "cobwebs" out of my head, and decide how to best handle his concern that made him wake up. Sometimes I have to firmly say "go back to sleep" (after I made sure he got what he needed...water or potty or whatever the concern). I've begun to also see a pattern in him that if he wakes up a second time in the night, I might as well stay up the whole night and do something just-in-case he wakes a third or forth time, because sometimes he just has a hard time getting back to sleep. For me, I have found that I'd rather be up and productive instead of re-awakened every time I have finally drifted back to sleep.
And that's just how it is. We moms find a rhythm in what we do. We learned our child or children, we learn more about ourselves too, and we adapt. We make it all work together however it has to. Perhaps for me, it will simply mean I will get some work done in the night, and take a nap sometime in the coming afternoon. It's gonna all work out, and there's no need to worry. That might not be how YOU do it (cope with surprise night wakings), but you will find the rhythm, the thing, the "that's how we roll" that works for you and your family.
I guess what I'm trying to get at here, is that motherhood can seem daunting to THINK about, but once you start, it flows... You will do fine. Love floods your heart, even if other factors cause you to think that it won't or to fear whatever fears you are fearing. Don't fear. You will do great!