Was just sitting in my room at like 3 am wide awake. I've been sort of staring off a lot recently and usually comes with negative thoughts so I've been avoiding doin that. This time I stared at my door for some time and eventually my arm started shaking then my whole body, felt like I was slightly stuck in place. Then when I was looking at my door with my hoodie hanging on to it, I kinda saw my hoodie turn into this black shadow mess kinda thing which scared the shit out of me and made leave my flat instantly and go outside for an hr to get away. First time having a panic attack with the lead up being so strange and I never thought I'd start to see things like that before a panic attack. Scared to stare off now as I'm certain I'll have another panic attack. 

Is it normal to slightly see stuff that absolutely aren't real even if it feels like it is at the same time? Should I be concerned?