This post may be disturbing to some people, so please be advised.

I have no idea what is wrong with me, but I needed to get some advice on what this may be.

Back in 2013, I suffered from the worst flu of my life. I wasn't able to function, and one day I woke up in a complete delirium. I thought I had killed people and that people were coming to kill me. I was having severe hallucinations. There was this indescribable feeling in my chest, something like a fear response, but not quite. I didn't know where I was. I barricaded myself in my room and continued to break down until my parents managed to get inside. Even then, it was a while before I calmed down.

Ever since then, I've had moments where that feeling in my chest comes back, brought on by stuff that doesn't make sense at all. Sometimes I'll be laying in bed and I'll feel the bed 'pushing against me too much', or weirder, I'll have vivid visualizations of imagery that sets off the feeling. Common visualization includes concentrated fat being pushed through a machine and sliced, or trees growing with limbs far too thick for their trunk. These images come into my head and I can't not think about them, until that chest feeling comes back. It's not that I'm hallucinating them, but more like they are so vividly visualized in my minds eye that I can practically see them in my head.

The feeling I get is like my sternum is being crushed. It feels sort of "hot" but that doesn't quite match the reality. I feel like I'm being crushed by the things around me, like I'm being pulled into my bed. It comes in pulses, and sort of feels like someone is slamming on piano keys, if that makes sense.

Does this sound like Anxiety? I'm not looking for a diagnosis here, but do you think I should set into this with the mindset of it being anxiety, or does it sound like something else? This has been affecting me for nearly 8 years now, and I'd like to get to the bottom of it once and for all.