Anyone else experience this?

I had to put my cat to sleep at the vet unexpectedly in the middle of the night because she was not eating, vomiting, and was already being treated for lymphoma. So around 3:30am she crossed the rainbow bridge and that night still traumatizes me to this day. It's been a month now but whenever I wake up around 3am (I have a baby to do night feeds) I feel great sadness and cry. It doesn't help because it's so dark and quiet that it makes me feel so depress.

I always watch videos and look at pictures to remember when she was happy before her health condition.. But whenever it's around the time of her passing, the pain is unbearable. I don't know how to overcome this.