Extreme sleep issues with 2 year old

This is regarding my daughter.  She has missed her father terribly, he has been 1000 miles away working for ten weeks.  Sleep issues didn't start until 5 weeks ago. She went from sleeping perfectly to fits of hysteria and waking.   I would leave the room when she was partially awake, and she would get herself the rest of the way asleep.She has a very regular routine of supper, bath, pj's, reading stories, and then getting in bed and me singing to her. Then I would leave and she would go to sleep.
The problems started  5 weeks ago. I went to put her down and when I left, she hurled herself screaming at the door. She had cried before, but nothing like this.  It was complete hysteria. she hit the door so hard it opened (we live in an old house). Since that night, I cannot leave the room with her awake. I have to stay until she is dead asleep. Even then, she keeps herself barely asleep, so that the slightest noise wakes her up. Ergo, when I try to leave the room as quietly as possible, she still manages to wake up. I have tried fans, keeping the ac running, light music. It can take up to 3 hours to get her asleep. After all that, she still wakes up several times throughout the night screaming and banging against the door until it opens.
That is the crux of the problem. I put a padlock on the outside of the door, but it makes too much noise to close and she wakes up when I lock it. When I do padlock the door, she wakes up instantly and will scream for hours, throwing herself against the door so that it shakes on its hinges. She is completely hysteric. She doesn't let up, either. The pediatrician suggested going back in every 10 - 15 minutes to reassure her, but that doesn't work either. We have gone for over FOUR hours with me going back in every 15 minutes. She calms down until I leave again, after which we start all over .
Please help us.  

[Kevin Kennedy, Ph.D.]

Placing a lock on the door with such a young child is not a good idea. It is only serving to panic her more. Stick to the routine you established and don't vary from it. You're going to have to bite the bullet to get through this. You cannot finesse it - there are no shortcuts. I'm assuming your daughter is no longer in a crib. Too many parents remove their child from a crib too early, before the child has sufficient impulse control to remain in a bed. Then the parent is left to struggle with the consequences of that decision. There is nor reason why children have to be out of a crib before the age of three even. It is  a place of security for the child. Suffice it to say that if you stick to the routine your daughter will return to her baseline level of functioning, but it's not going to be easy. Many aspects of parenting are not easy.

[janedoe04]

Kevin, I did not remove her from her crib by choice.  She starting climbing out consistently at 18 months and we were worried she would hurt herself.