Difficult sacrifice

For me,  this had been difficult.   This has been a difficult sacrifice to make.   I know my son is where he is suppose to be.   I know the Lord is watching over him.   I am happy to know that the Lord is raising him,  so why then am I struggling with him being gone?   Why is it that I miss him so much?   I don't tell him this in my letters, as much as I want to.   
As long as I am busy I am ok, but honestly,  can I stay busy everyday for 24 hours for the next two years?   I also find as long as I am not home I am a little bit better.
Right now it is 8:07am.  Quite often Garrett would wake up at this hour.; he would be the only one awake in the House.   I would find I would wake up at this hour as well and go out in the family room, where he would go.   Usually we didn't exchange many words but a simple "Hello,  how are you?   How did you sleep? "  then we would talk about our plans for the day or the news that took place over night.    Quite often you would find Garrett on the computer pouring over the news; he was a news junkie.
I am finding I am having a hard time going to places we would go to.   I would remember the last time we went there as a family.   
I just miss that kid.   I know he is in the best of hands.   I really wouldn't want him doing anything else.  So why then does this sacrifice have to be so difficult?  
There are times the missing him feels so crushing.  It feels like a giant weight has been placed upon you.  The only way I can release it is to cry usually.   I often wonder if I am tyne only mom who feels this way.   I wonder am I the only mom who will die from heartache (I know,  probably being a bit dramatic,  but honestly, that is how I feel).
I am still not a fan of the question, "how are you doing? "
Why does this sacrifice have to be so hard?