New grad RN. Any advice?

I’m having a hard time adjusting to being a new RN. However, I’m getting more comfortable little by little with each new shift. I work in a cardiac ICU. I’m learning that nursing has so much gray area. It’s like ‘let’s do this and pray that it works’. I’m more of a black and white person. I’m also dealing with some mental health issues. Currently fighting my own brain every work day. Creating thoughts of what I think someone is thinking but no proof.

If any of you have any new grad tips, that’ll be amazing!!