I wept when I read your post and am still weeping. This is NOT God's end for your son. My father says that the memory of the righteous is a blessing. Don't forget all the fun times you had with your wife and daughter preparing for him and dreaming for him. Planning for him and loving him. Those memories can never be taken away.
Know too that the Good Lord, the Creator, also lost a son and knows how you feel. Seek Him and the others on this board that have gone through something similiar. We were not made to bear this burden by ourselves.
Your wife and daughter need you to be strong and they will be looking to you for support, strength and love.
You and your family will be in our prayers and you have our deepest condolences. You can PM me if you ever wish to talk, weep or even just yell.