your relationship is no good for either of you. you are both violant and that is no good for your children especially.
You need to seperate and BOTH take anger managment councelling.
Well done for admiting your role in what has happened but please be aware that no matter what you did, you did not deserve to be punched.
If you think it would be safe to do so you need to sit and discuss what happened and the fact that it is probably (deffinately) best for you both to split, and the practicalities of what that would involve.
If you don't feel that would be achievable without further violance or aggression then you must just leave.
You have specifically asked for someone with experaince to offer some advice (glad you have ignored Salla....is she some freako from another site or something?)
well as is well documented here i have experianced quite severe domestic abuse and am now happily free from my ex.
youworry about what will happen next time you row, i will give you a most probable case.
something silly will cause a row, you will both be discussing it and it will get heated, then you will get scared. you realise that you are not just discussing, your actually arguing. he is getting angry and you remember the black eye. he see's your fear and becomes even more angry that you are afraid of him. you get angry that your afraid of him so you pretend not to be. you shout louder trying to hide your fear.
he gets even more angry and WALLOP!
it soon becomes less anger and more fear.
shorter periods between the row's, quicker to the punch.
teh violance becomes more frequent and more aggressive.
All he will have learnt from this scenario is not to hit you in the face as it leaves a visible mark.
I know its not what you wanted to hear but i have 7 years experience im afraid.
The first few months i was convinced that although we argued quite aggressivly he would never ever hit me.
By the time i had left i had been kicked, punched, slapped, had knives held to my throat, screwdrivers thrown at me, raped, spat at, pulled around by my hair.....the list could go on for pages.
Please, for the sake of your children get the help that you both need now and seperate