Please, please, please take a deep breath....you will be OK. You are not a lost cause, and you WILL make it. If you read enough of these posts, there are a million of them from licensed RNs in their first year, that feel even worse than you do because they have finished school, got their license, and have been working, and feel like they are just not getting it. It is HARD. There is a lot to learn. There is really no such thing as a "critical care student," most ICU's don't even take nurses without several years of med surg experience. And that is for a very good reason. Some students/nurses will pick it up quicker than others, and if you compare yourself to them you will feel miserable. So don't do it. Review the stuff that you fell short on, and keep going.