Why I grieve

I just read a very touching post from a friend,  remembering his late mother beautifully on her angelversarrry today and it helped me put into perspective (at least for the moment) why I hurt so badly.  People often seem to feel the need to remind me that Andy is "In a better place" which makes me feel guilty for the pain I feel.  I should be happy for him right?  But I don't grieve for him.  He IS in a better place and I do believe he feels no sadness, no tears, no pain.  So why am I hurting so bad?  It's like he left this huge hole, a hole that I used to pour all the love I had for him into and now it just spills into ....nothing.  Maybe that's why so many of us feel the very strong need to DO SOMETHING in memory of our child/loved one?  We need to direct that love to something concrete and tangible.  We NEED to feel them receive it.  Especially as mothers/parents it's particularly hard because we love constantly and unconditionally and are bonded to for all of OUR lives  Grief is love with no place to go?