i know how you feel,i've felt that choking pain before more then once. you'd think i've learned from it the first time? i've spend weeks smoking and crying and not eating cause i couldn't nourish myself..
anyway, time will make it managable. some hurts don't go away, they just fade...we learn to live with them and around them and with time a new door of love will open and things will be ok again. try to see things in perspective even tho it seems impossible.
i can't tell you how to get over the pain...but i can tell you is that you will be ok, you are strong. focus on your son and yourself. you don't know what the future holds but it will be much better then what you are feeling right now! yah, maybe there is no such thing as forever, so in that case this horrible feeling won't last forever either!