ready to leave, need advice

I am 7 months into my grad year at NICU and have been feeling this way for a while now. I thought I’d be able to handle it but the environment is so high pressure and unpredictable that I am in fight or flight the entire time I’m there, not to mention the pre and post shift anxiety that rules most of my days off. I’ve stopped eating well, stopped going to the gym, have pushed people I love away just because I am so stressed and can’t handle it. I have been looking for other jobs but haven’t been able to secure anything yet. I don’t know how much longer I can keep going, every shift I lose myself a little bit more. I’m working the next 3 days and am literally feeling like I might have to give in my notice immediately if I get an assignment that makes me cry from stress again. I feel like I’m hitting my threshold of what I can bare. I’ve opened up to someone in management about how I’ve been feeling and they were fully supportive but recommended that I secure another job before leaving. Yet I just feel so sad and stressed every week :( I am even jealous of my friends working corporate, this job has made me want to leave nursing all together because the responsibility of having life in your hands is too much for me. Ik it sounds crazy being a nurse but I think I just didn’t realise what I was getting myself into after high school. I have loved coming to NICU and love the babies/families don’t get me wrong, I just find it too stressful. How bad would it be to give my 4 weeks notice without another job lined up? I can afford it short term but would feel like I failed and let the unit down. I feel like I’m stuck and it’s the worst feeling ever, any advice would be appreciated