Training for taking body blows
I know this may have been discussed before, I searched, but my question is a little bit different.
I know people train their body with medicine balls, sit-ups and variations of it, and finding a partner and punching each other's body and those kind of things.
I am a southpaw and body blows hurt a lot especially to the liver because southpaws have their right side of the body facing the opponent, and that's where the liver is big. I suffer so much both in boxing and kickboxing during sparring. I've never been knocked down by head blows, but I have gone down 6 or 7 times in sparring throughout the 2 years of boxing and kickboxing by body punch and body kick.
So I wanted to train my body to be better at taking punches to the body when it comes when I just couldn't see it coming (most of the times, I would move my body so the punch lands missing the vital spot and etc, but I'm a human and I fail sometimes.
However, this body training requires two or more people, and the training I do isn't enough for me in my opinion. So I want to know of a way that I could do alone to train my body. I do sit-ups of course and some variations of them but what else can I do (should do)?