Breaking a child's will without breaking her spirit

I realize that the title of this post might be misleading.  This is not a "how to" kind of post.  I have no idea how to do it.

In this mothering journey, I have come to realize that I have no idea how to do most things.  I just rely on the goodness of God and the kindness of my husband who sometimes takes the baby and lets me sleep in.

I'm writing this post at 4:30 in the morning.  Camille woke up crying at around 3:15am.  Instinctively, I knew she woke up because she was thirsty/hungry.  I didn't feel like she nursed very well before bed because she was a little hyperactive and wanted to crawl around.  I had to switch from side-lying nursing to picking her up and holding her to nurse in order to keep her from crawling away.  Still didn't work.

I waited until 3:35 to pick her up.  Yes, I let her cry bloody murder for 20 minutes.  (Thankfully, we must have thick walls because the neighbors insist that they never hear her cry.  I'm also thankful that Chin can sleep through her crying, too, for the most part.) 

I really struggled with the decision to pick her up.  If I pick her up and nurse her, will she develop this pattern of always wanting to be nursed in the middle of the night?  Should I just leave her to cry until she is so tired she will pass out again?  What kind of a mother would be so cruel?  What do my instincts say?  (Yes, I am plagued by this awful question all the time!)

I decided to heat up a ThinkBaby transitional sippy cup with about 3 oz of pumped milk and a little bit of formula for a calorie booster.  Screeeeeeeeeeeeeeeeeeams and struggles and gulps of milk spat out on my face and all over the bed.  No go.  Rest a little bit.  Try again.  Same results.  Rest a little bit.  Try again.  Same results. 

Then I tried to reason with her.  "Beloved child, if you don't take the milk from this cup, I am putting you back in bed.  This is Mommy's milk.  It's good for you.  It will make you less thirsty."  Who expects anyone to think straight at four in the morning?!

Try again.  Same results.

Then I think about her recent weight loss, undoubtedly due to the fact that she's simply not getting enough milk.  I think about nursing her.

But am I giving into her strong will?  How I break her will...without breaking her spirit?  And without breaking the trust that I have built with her?

Then I think of articles like this one.  Those natural parenting writings that "never intend to guilt you" but inevitably do so.

I don't know.  I don't know what to do.  She finally fell asleep in my arm.  I am sure she's still thirsty and hungry. 

What do I do?

I feel incredibly alone.