Hangover feeling from intense cardio?

I've played basketball all of my life and now in my early 40s. I had a game last week and felt like I overdid it (no subs), to the point of feeling light headed and a little weak.

Two days later, I lifted weights fine and followed that with yard work. I was feeling a little light headed again during the outside yard work but assumed that it was due to the early heat wave we're having and my body not being fully adjusted to it.

Now, it's a week later and I'm still feeling light headed at times and trying to focus on taking deeper breaths. My normal breathing seems to be more shallow now. It's sort of subtle so not sure if something to be worried about or just a slow recovery from last week. I get seasonal allergies and could be another possibility.