If you were my student, then this would be the first thing I would recommend. If you can't stay calm enough for your brain to analyze what is coming at you then much of what the others are recommending isn't going to be use to you.
When I teach my students how to fight. I refer to this as "sitting in the storm." What this means is that my first move is to protect my head and at the same time watch and analyze my opponent for an opening to either, counter, attack, escape, bait, or move to a position that give me an advantage or takes me out of danger. I make students learn how to do this without closing their eyes. They need to see every punch even if it slips in and hits them in the nose.
Here's of a video of me "sitting in the storm." My sparring partner rushes in with some good combinations. I sacrifice my stomach because I know I can take a punch there better than I can take in my head. So it's really not much of a sacrifice. When you watch the slow motion part at the end, you can see that my punch follows as his punch retreats. You can see how my one punch stuns him and knocks him backwards. It wasn't a hard punch just a well placed one. In this video that punch landed on his heart. Also pay attention to my head and you can tell that I'm analyzing him while he's attacking me.
You don't have to go fancy when dealing with charging punches, but you will always have to be able to analyze what is coming at you, while you are defending against a punch.