I saved my boyfriends life but now I am traumatized and have bad dreams every night

My boyfriend suffered ventricular fibrilation two weeks ago and after being in critical condition he has made it and luckily his brain seems to be working well.
I found him gasping, turning red with blue lips and then stopping breathing in the middle of the night. Ofc I called EMS immediately and upon order I started resuscitation. Luckily they arrived in 8min after I dialed EMS 🙏🏻 I knew it was something very very bad as my uncle died of something similar 3 years ago. Back then he lived in countryside without proper medical access. Fastforward they were able to stabilize him (thanks god he didnt die on spot) and the doctor said for whatever reason it was ventricular fibrilation which means almost certainly death if he hadnt been rescued in time. Literally every second and minute matters. Even with medical help, the survival rate is like 45%. So he was immensely lucky. He was released from the hospital yesterday after 2 weeks.
The thing is I feel to be traumatized after this experience. Whenever I close my eyes, I replay the night in my head and I cant stop it. I also cant stop thinking of scenarios with bad endings. What if I didnt wake up? It happened at 4AM when I am usually deep in sleep. What if I panicked and wasnt fast enough to call EMS? What if he slept alone that night? The doctor said if he had been in that state for few more minutes, we would have found him dead in the bed… All nurses have been telling me I did good job and saved his life. But I feel this guilt that I could have done better job such as waking up earlier or preventing it. I HATED BEING HELPLESS at that moment. I hated that I couldnt breathe for him or fix his heart. In addition to that I have nightmares past few days after his condition has returned to normal. I regularly wake up in the night to check whether the person next to me is breathing. In my dreams, either he or someone else is dying and turning blue. I often wake up crying or being desperate after that dream. My bf tries to calm me but his condition isnt ideal. Even though, he is released from the hospital, he is very dependent on others, gets easily tired, has difficulty of breathing properly etc. The doctor said its like being born again. His whole body incl brain had to be reset. Obviously, I cant be more happier for him but the whole situation is eating me up. Has anyone faced similar situation? How to overcome it? Just wait for time to heal?