If your opponent is a good boxer and you’re not it’s recommended that you don’t try and trade punches. It’s the same with judo. If someone is a black belt and really good at tossing human beings into the sky it’s not a good idea to engage them whilst standing. I’ve learn the latter the hard way whilst training for Brazilian jiu-jitsu. Go toe-to-toe with a judoka and you’re gonna get thrown. It’s a fact.
But being thrown isn’t too bad or painful if you do one of two things. The first way to limit the oww-factor of being thrown is to make sure the person throwing you is a friend. Or, at the least, a training partner. That way they’ll be less inclined to 1) throw you high and slam you into the mat and 2) come down hard on your head/neck/ribs.
The second way to limit the ow-factor of being thrown is to go with it. To not resist. Which is hard. If someone pulls you one way, it’s instinct to react by pulling in the opposite direction. So when a judoka draws you in and gets underneath your hips, you automatically try to pull back and away. But that is the way of pain. By resisting, by tightening and tensing up, you make the impact all the harder. But if you accept that you’re going to be thrown, if you release the tension, the throw is smoother, the landing is less violent, and you don’t end up wondering how foam mats feel like concrete when hit at a particular speed.