It's my usual work day, in the office. So I had to run some errand and I walked slightly fast over it (wasn't running or anything), and when I'm back into office. I noticed my heart rate actually shot up and I felt a bit dizzy with my palms slightly sweaty.

I wasn't sweating but I'm feeling a lot of gas in my stomach and I burped/belched, or trying to burp cause it feels stuck, and I get this pressure feeling in my chest.

It does feel like I'm at the edge of collapsing (slight impeding doom feeling) and feels like I'm getting a heart attack. I'm not sure if this is a panic attack or anxiety attack but I felt generally better after an hour or two after sitting still i.e. resting, it does take that long. 

Anyone else experience something similar?