Anxiety/panic attacks??

I don't really have anyone I feel comfortable talking about this with besides my boyfriend so that's why I'm posting this here for hopefully advice/opinions. But basically, I lost my grandmother a few months back. She was truly the most important person in my life and nothing has felt real since she left. Her death came very quickly and unexpectedly, but I was still there. I watched her pass.

But anyway, I'm writing this because recently I've had nights where I end up in tears and just start sobbing until I'm hyperventilating because my mind starts to make me remember events from the day she passed. I try so hard to ignore it and get my mind somewhere else, but it's like once I think of her I'm screwed and there's no way out of it.

I've had these "mental breakdowns" before where I just lose control of my emotions and end up sobbing like this, but these episodes have been different. It's a constant cycle of tears to sobs to panic, then back to calm. And then more tears, and the cycle continues. It feels like my entire soul is ripped out of my chest and I can't breathe and I'm just begging myself to not think of that day, but I can't make it stop.

I don't know if this is an anxiety or panic attack or if it's something else since it's specifically focused on that one day. But I really would greatly appreciate getting anyone's opinion or view of this situation. Please let me know what you think. I feel like I'm going crazy