In my experience, even small losses can get chained together, like a magician's scarf, and feel really really big. It is a big loss for you, and I'm sorry that you have to go through it. But on the up side, when I have gone through grief and come out the other side, it is more bittersweet than bitter. I am grateful for having had this person in my life and for what I learned from them. It is really true what they say at most funerals, that we carry people with us, or as the poet cummings wrote:

here is the deepest secret nobody knows (here is the root of the root and the bud of the bud and the sky of the sky of a tree called life;which grows higher than soul can hope or mind can hide) and this is the wonder that's keeping the stars apart i carry your heart(i carry it in my heart)