I too started straight out of nursing school in the IMC/ICU. I am now nine years a nurse and here is my advice: buy a good physiopathology book, an excellent critical care reference book, a pocket reference book to keep on your person; get a good preceptor and understanding supervisor; put night work (when you are stronger) in your rotation. In that way, you can learn to work more independently and with less resources. Study when you can, but don't overload or "overthink" everything. Expect to cry, expect to make mistakes, and demand to learn. Eventually, you will be a strong ICU nurse.