A.J.
There was a post a few weeks ago about a 12 month old doing the same thing after a week of the crying-it-out method. Is this similar? I guess i'd need more information as well. If it is related to CIO then my recommendation is to stop.
If it isn't related, this behavior suggests your daughter feels very very very anxious about being left alone so you might want to start with making the transition longer and very nurturing and calm. Have gentle music playing, rock her for awhile so she feels your closeness and the safety of. After putting her in her crib, don't leave but maybe keep your hand on her tummy while 'shhhhhh'in' and or let her hold your hand.
With this extreme of a reaction, now is NOT the time to try instilling rules around her needing to self sooth. Spend the next few weeks soothing her and teaching her how to self sooth. Provide her with something soft and visually show her how soothing it makes mommy feel then give it to her to try. This might take several tries so stick with it.
After she is able to feel secure enough to stop self harming (because this is what she is doing in the confusion of her anxiety), then and only then start to slowly change the routine.
Again, without knowing the degree to which this is happening or the context, it's difficult to say 'why' she is doing this short of she is very fearful of being left alone. She is waaaaaayyyyy too young for this to be viewed as an attention seeking behavior and she needs to feel safe first and foremost.
Are you her primary caregiver? Is she being left alone too much? Only you know what she has experienced thus far in her life so are in the best position to know the answer to these questions.
Best wishes and please keep a close eye on her! Babies can choke on their own vomit so spend as much time as needed to help her feel safe, nurtured, and less anxious.
Best wishes:)