Feeling like aids after a run

I've started running during my walks. Not going too hard at it. Probably more closer to a jog (a fantastic NZ invention) than anything else. I do short runs, the first blitz I did was 450 metres long on the road. It was pretty flat so incline isn't to blame here. I started getting huffed out by the 400 metre mark, and I went back to walking at 450 metres because I was a nauseated faggot. I was feeling pretty light headed and a bit dizzy. I was huffing and puffing trying to capture my breath. My legs weren't the limitation. It was the nauseous feeling that made me go back to walking. I like running but this feeling sucks. Any tips?