Crying Times

So at some point every new mother must humble themselves and ask for advise from more seasoned mothers. This is my cry for help. My daughter was doing a lot of crying today and every day for the past month whenever I leave her alone. I know she is going through some separation issues, but I don't know how much is too much. Today was my breaking point. Here's the scoop: I went to church and attempted to leave my daughter in the nursery. The worker had to pry her little fingers from around my arm and lift her up as she screamed bloody murder. I walked outside the room and cried for 10 minutes myself as I listened to my daughter's distress. A fellow worker took compassion on me and calmly told me that she would get me if my daughter continued to cry for 15 minutes. I took the tissue she offered and headed to the service. While trying to sing praises to my God, whom I had come to worship, my thoughts and heart were with my daughter. I lasted 30 minutes, but still felt the desire to check on Nevaeh. Needless to say, as I headed down the hall that held her classroom, I could still hear her screaming for me. So I boldly walked in, told them that I could not let her cry anymore and that we were leaving. I was told that I needed to leave her b/c it was only going to get harder if I took her now. I was informed that I had to give it some time. Now, I am not one of those mothers who coddles her child. In fact, my husband and I successfully used the cry-it-out sleeping technique. But how much time is enough? Was I hasty in retrieving my child after 30 mins? Or should I have let her cry for 2 hours as I was informed some parents had done? Is this really harder on me than on the child as the worker thought appropriate to share with me? This isn't just a church thing...it's an every time I leave her alone with someone thing. Whether at the gym for an hour while I work out or at church or even in another room with a sitter while I'm at a Bible study. I just don't know what to do and I desperately want to do what is right by her. Any advice would be greatly helpful. Thanks