If you know thats what you're interested it should be awesome. I did my capstone in critical care and such a great experience. I recommend you start reading up on your vents and watch as many youtube videos as you can until you start to understand ...
I recently graduated and took a MICU job right out of college. My only previous ICU experience was my senior capstone so it's definitely possible. My advice would be to look for a residency program that takes new grads and be willing to move if you...
I thought I bombed mine too after 75, but I passed. If you know your stuff, did well on your ati tests, and prepped well you should be fine. Good luck!