Is it traumatic being with a cat while they are put down?

I think my 12 year old cat will need to be put down soon. She is having trouble breathing and I strongly suspect it is her heart, as she has a known heart murmur.

I am her best friend and want to be there for her if that happens, but I am worried it will traumatise me. I have anxiety so struggle with my mental health as it is. Can anybody share their experience with being present when their cat was put down? How can I help myself cope with the memory of seeing it happen?

EDIT: wow so many responses! Thank you all so much for sharing about such a difficult subject. Just to reassure everyone, I am 100% going to be there with my cat, I am just very worried about how scary I will find it. It is very comforting to read so many message reassuring me that it is not as scary as I am imagining. I can’t reply to you all but I am reading evety response ❤️

EDIT 2: just to clarify that this post is not me asking for help with deciding whether to be there with my cat - I definitely will be. I just wanted some advice about how to look after myself during and after. I am sorry if that is selfish, but I am just very scared about seeing my little kitty be put down. I promise I will be with her and that most of my worries are about her and how I can best look after her. I’m just scared.