Meadow.….you ask if falling on the ground, in a rage and slapping your son is because of your "broken heart"...…
I suggest that it most likely comes from a place of fear....fear of not being able to control your son's behavior...and the feeling of helplessness that can come from that.....
I think, that, sometimes, parents fear that the child's behavior is a personal reflection on themselves...which it is not....It does strike fear to the parents sense of self-esteem and personal ego....so, that fear can be expressed in form of great anger. great fear=great anger. Anger is usually not the primary emotion..it is usually a cover emotion for underlying fear/sadness/frustration.
Here is m y suggestion (if you want it)….Apologize to your son for your loss of control...without any excuses. Just express your regret, period. And, then....ask him what you can do to help him with his school work.....
Remember, that he may be distracted with lots of emotional things that you have no idea about....Try to find time to talk to him about his school work....and find out what is really going on...with the goal of helping him. Also, try to spend some individual time with him...and see if he will talk about what else might be going on with him, in his world. Surely, the events between you and your man have some effect on the home atmosphere.....and children of any age absorb this stuff...even if they aren't talking about it.
15yrs. is a very critical age for boys...and, they need parental attention and time, more than ever.... Perhaps, this is something that your counselor can help you with....
As time goes on, your man will not be a part of your life...but your son will always be.....This could be a time to build a closer relationship with your son.....