It sounds like you are just adjusting to the ICU. There is always so much to learn, it is hard as a new grad. I started as a new grad in the ICU and felt like I was going to throww-up each and every day that I worked. By the time I hit 6 months, I felt ready to be separated from my preceptor and take care of a patient by myeself. And it is true... two months in you don't know much, that is okay, you have only been an RN for 2 months... You can't have learned everything. It takes time to learn procedures, tasks, diagnosis, etc. It will likely take a year before you feel some type of oh, I know some things.
Give yourself a little bit of credit, you are two months in, have learned a lot, and still have time to learn more. if you have classes as part of your orientation, ask questions about specific patients or diagnosis then and see how your fellow new RNs are.
Also make sure on your days off you do something fun , rest, and focus on some non-work related things. Take care and good luck.