Self defense gets you off.
self defense and defense of others gets you off without a doubt
heres how it happend
him and her were arguing heatedly, you was watching as it grabbed your attention, you saw him hit her, you went over and asked him what he thought he was doing as (of course) he was raising his hand again.
he told you 'stay the **** out of his buissness' and hit you
you defended yourself
now disregard and deny any witnessess 😛
I think you have a solid self defense plea if you believe she was in danger... a man hitting a woman is understandable if you thought she was in physical danger. Him threatening you has no bearing on whether you were acting in defense or not. And I'm sure there are a bunch of good witnesses around that could support your side of the story... still find some one good to represent you, that is key.