Self Control

I've been working on a lot of different things with my five year old son, but I'd specifically like to ask about self-control this week. He doesn't seem to understand that he regularly hurts people, no matter how we explain and show him how he's hurting us. He struggles to maintain boundaries when he's excited or hyper, and it's especially scary when he's trying to play with his 7 month old sister. He has almost crushed her a couple of times, and I hate to constantly be saying "you've lost your privilege of being near your sister (or whoever he is trying to "play" with)," but it frequently seems to be the only way to keep people out of harm's way. He generally doesn't seem to be doing it maliciously, but he doesn't seem to care whatsoever about boundaries that others set… Also, he is VERY sensitive when he gets hurt or when somebody does something even remotely similar back to him (even after several warnings and explanations). We've been dealing with this for years, but it's been especially concerning since he's gotten his little sister. Any tips?