Consider the following - maybe your managers realize how vague task is, they also realize that you put a lot of pressure on yourself to make it, as I understand without strong support. I have been many times in same situation, usually when this happened first: I read "The humble programmer" :-),which reminds me that there is always something that I don't know, second: look again on the task and try to find its challenges, things that after completing them will make me a better programmer.