The person you fell in love with probably wasn't abusive to you when you first fell in love with them. In fact, abusive partners often initially appear completely the opposite being charming, kind, attentive and eager to commit. As a result of this, normally people will see the non-abusive side of their partner as 'the real them' and the abusive side as not really them and something that may well have been caused by some kind of life experience. Sadly, however, the abusive part of them is as much a part of the 'real' them as the non-abusive part and sometimes more so. It can be that they are kind or do something nice as a means to an end rather than kindness for its own sake. Part of being able to deal with domestic abuse involves starting to accept that you can't have one part of this person without the other, unless they accept responsibility for their actions and get help through things such as perpetrator programmes to address their issues.