Obviously you felt like things had to change if you hired an expert to help you. I don't want to steer you off of your course if this is what you have decided to do, but I thought I would tell you my experience. I have a 6 year old daughter and a 4 year old son. My daughter had a lot of struggles sleeping as a baby. Laying her down in her crib after she fell asleep was like laying her on egg shells. If I didn't do it just right or she wasn't sound asleep she often woke up crying. She thought that she needed to be held or sleeping with one of us. We questioned whether she was cold and needed the warmth, whether her stomach was bothering her and being more upright helped (we did by a pad that you put in the bed that keeps their top half more elevated and did feel like this actually helped some). I had read a lot of books as well and I was convinced that I didn't want her sleeping in bed with us, although there were a few nights that I was so exhausted I broke my own rule, but not very often. We had a Lazy Boy in her room and I tried not to fall asleep in it with her, but my husband often did.
We tried contolled crying and it did not work. She would work herself up more and more and in my opinion 45 minutes of crying is WAY too much. I honestly never let it get that high. I ended up waiting until she was about 16 months. At that point I knew that she understood us when we were talking to her. I would sit in the Lazy Boy in her room and tell her that if she laid down in her crib I would sit in the Lazy Boy next to her and hold her hand or pat her back but if she wouldn't lay down I would leave the room. It took a number of nights of going in and out of her room, but she eventually got it.
When whe was 2 and a half her brother was born and she transitioned from the crib to a queen sized bed. I would read her books laying in bed with her and then cuddle with her. She would sometimes fall asleep in bed with me and other times I would leave. We had a few battles when I left a few nights, but we eventually figured out that she could read the numbers on her clock. I told her that when the first number was an 8, I had to leave, but I would spend about an hour with her before that.
I won't say there weren't really bad nights where she was more clingy than others, but I will tell you by the time she was 3 she went to bed very well and stayed in bed all night. I will also tell you at 6 she is an awesome sleeper. We still read books in bed each night for about 15 minutes, have about 5 minutes of cuddle time and then she goes to sleep.
My son was the opposite of my daughter. From day one he liked to sleep and had no problems doing it on his own. We used to joke that we could throw him into his crib from the Lazy Boy and he would stay asleep. When he hit 3, all of a sudden he didn't think going to bed was as important and we have had a number of battles with him at bed time and he has had a number of nights where he needed extra cuddle time and/or has had a toy put up for not staying in bed at bed time.
I guess my way too long point is, kids are all different and as a mom you have to decide what you are comfortable with. You can read all of the books you want, but your child is probably not going to fit into any of them perfectly. Take what you feel is important from them and find the route that suits your family. I feel like the more important piece of information I got from all of the books is that sometimes not sleeping is a sign that they may need more sleep. Moving bed time earlier or working to ensure that a nap happens sometimes solves our bed time problems when they creep up.
Good luck and know that there are many, many Moms out there that understand your struggles. I know it doesn't help much now, but this too will pass and soon you will be looking back on it and offering advice to others.