I disagree with the posters that say that letting your child cry it out causes mistrust. And Dr. Sears' research indicating that crying it out can affect the baby's brain development is after "Weeks and weeks" of crying it out. If you read the literature, they use words like "routinely separated from parents in a stressful way". If you follow a sleep training plan, where you check on your children at intervals--showing them that you are not abandoning them, and your child responds to the sleep training, then you don't have to "routinely" let them cry or let them cry it out for "weeks and weeks" because for many children (I didn't say all children) it works in just a few days.
We co-slept until she was 3 months old at which time my husband's snoring woke her up. I nursed my daughter to sleep. Then when she would still be awake after nursing, I would bounce her to sleep. At 4 months old she would need to be bounced/rocked/shushed for 30-60 minutes at a time for every nap and night waking--and she was waking 5 times a night. I was exhausted and miserable--and so was she. Everyone said that the smiley little baby I had was disappearing. We used the Ferber method, with the approval of our pediatrician (who is a well-loved pediatrician of over 30 years in practice whose patients now come back to her with their children...and they aren't all walking around with attachment disorders) and in 2 nights, our daughter was able to put herself to sleep.
In less than a week, she was a happier baby. Instead of waking up crying and in distress, as she used to. She would wake up happy and babbling. She is very much in love with me and my husband and trusts us more than anyone. I don't feel any lack of bond. And she's not crying herself to sleep anymore. I nurse her until she's drowsy, put her in her crib, she turns over and plays with her lovey/stuffed animal for a few minutes, then falls to sleep.
We did not do this to force her to sleep through the night. Now, even 3.5 months later, I still get up and feed her once a night. The other night she woke up 3 times and I fed her all three times, I am not ignoring her needs--she's teething right now and that's comforting to her and I'd rather give her breastmilk than tylenol, so that's what I choose to do.
Letting your child cry it out does not make you a monster. I am convinced that it saved our lives. I was practically falling asleep on the road as I would drive me and my daughter around. I tried the solutions offered in the "No Cry Sleep Solution" for a month, and they just did not work for us. If they work for you, that would be fantastic--listening to your child cry for a long time is the most stressful thing, I cried just as much as she did.
But at 8 months, she is the smiliest, happiest, healthiest baby. She sleeps from 7:30pm to 7:30am (getting up anywhere from 0-3 times, but most days of the week, just once). She takes 3 naps a day that are each at least 45 minutes, some up to 2 hours.
Remember, ALL BABIES ARE DIFFERENT. For some people, keeping their child awake later works, for some people, cutting out a nap works, but for others--this may be setting you up for having an over-tired baby.
My bottom line is: yes, she's waking 4-5 times a night because you've trained her to fall asleep with a nipple in her mouth and when she awakes partially (like all babies do during the night, all humans do) and it's not there, she gets upset.
If you can get her to fall asleep without nursing...try the non-cry-it-out solutions first! But if you have to, don't feel like you're a bad parent. You're not. You're making the best choices you can.