Numb so sorry this has happened to you.
It is very easy for people to sit on a thread such as this one and say ?leave him?, ?it doesn?t matter what other people think?, but this is not their situation, and while we all have opinions on these matters ultimately many of us advise based on our own opinion of what we would do if it were us, and even those who are advising from their own experiences most likely didn?t leave after the first incident either because we all want to think that it was a one-off and would never happen again.
The reality is that there probably are people who hit their partner as a one off and never do it again. But we don?t hear about those situations because like you, people are to ashamed/embarrassed to talk about it to anyone, and if it never happens again they probably never feel the need to talk about it as time passes.
But this isn?t really about whether he will or won?t do it again, it?s about the fact he?s crossed a line, and whether you can really get past that, and whether you will be able to trust him again and feel safe. I know I personally couldn?t, and it wouldn?t matter to me how many anger management classes he went to, if a man was violent to me just once then he will have crossed a line and there would be no going back. But not all women are that strong, and many have been broken down emotionally before it gets to a point of physical violence, so they feel they have nowhere to go.
Only you can decide where you go from here. Others will have opinions but no-one has the right to judge you or criticise you for whatever decision you make, it is your life. But:
You have nothing to feel ashamed about. You have done nothing wrong, he has.
You need to seek medical attention for your arm, and again, there is no reason why you shouldn?t tell the gp what has happened. In fact telling the gp what has happened puts you in control and makes a statement that you did nothing wrong.
Please speak to someone impartial such as women?s aid. They will give you practical advice what to do. Even if you don?t feel that you can or want to leave right now, that doesn?t mean that won?t change one day in the future, and if it does, then you can take steps now so that if/when the time comes, you will be ready.
Please take care of yourself, and whatever happens, just remember that you did not deserve this, and you did nothing wrong.