I second Nightnurse's comments.

I have had two less severe concussions before that were work related. Both had some minor symptoms that resolved within 5 days.

This year I was in a car accident, and directly after started feeling nauseous. I went to the ER to get checked out and they diagnosed a concussion.

As the next week went on I developed new symptoms and spiraled downwards from there.

I would get it checked out. Directly after my accident, I didn't think it was a big deal and I'd be fine after a day or two. It was my bf who pushed me to go to the ER. It's now 7 months later and I'm still dealing with symptoms. Further, previous head trauma leads your brain to be more likely to experience concussion like symptoms when you reinjure your brain, even if the injury seems like a minor one. Cummulative brain trauma makes recovery longer and harder each time.

Boxing is dangerous for your already injured brain. It may be something to think about.

Definitely get your brain checked out! A poorly functioning brain really damages all other parts of your life!