Man, something very similar just happened to me last night.......
The pre killed rat that I fed Xaero sat for like two hours before he decided to eat it. Of course then when he was trying to get it down, the front legs had begun to get stiff and he couldn't get them to fold back while swallowing. So he wrestled with it for like fifteen minutes. Looked exhausting! After many failed attempts he finally just heaved it back out (Uber Gross!) and gave up. The head and shoulders of the rat was all slimy and ......well you get the idea.
Naturally I felt bad about it, having not botched a feeding until now. I know how you feel, seeing the food go out instead of in is distressing! I plan on just waiting a day or so and trying again.
As far as Apock suddenly going bulemic on you, the other members' advice posted above is as good as any I'd give you, check your temps and humidity and size of prey, wait a day or two or three and try again.
Sending you good feeding juju :wink: