controlled crying

What is everyone's view on controlled crying??? I had a sleep consultant stay at my house last night but it was the most traumatic night of my life!!!! I am heart broken that I allowed my baby to cry like he did!!! Now she's given me a routine to follow during the days I'm just so confused and heart broken I don't know whether I should give it a go or stop! I want to stop, I feel horrible and I'm extremely upset about it! It's just that my 6 month old wakes every 2 hrs at night and I have to nurse him back to sleep which makes me exhausted every day! But honestly I would rather live like that than to do what I did last night :(