Since this is under "Why do people stay in abusive relationships", I will answer this according to the assumption that you are speaking of someone who is abusive (physically or emotionally, they are both abuse).
Apologies are often just added manipulation in these cases. Is this man seeking help from a therapist? What is he doing to change the pattern of behavior?
Regardless, LEAVE any relationship that is abusive as it only gets worse. If he is seeking therapy and you wish to try again, do so only after being a part of those therapy session and only with the blessing of the therapist.
Honestly, even therapy leaves me hesitant but it's a better option than one who just keeps saying he is sorry. Sorry doesn't mean they will stop, even promises of stopping doesn't mean they will stop either.
Get out, get out now and then seek a recovery therapist for yourself to help you not repeat this pattern for yourself.