You are right. It will get better. Six months is still very early. And please don't feel like a cad when the pain isn't as bad, as if you care less about her. Some people make that mistake.
I lost a child eight years ago so I'm somewhat of an authority of blinding unendurable pain. Time helps.
I'm sorry for your loss. We were lucky to have so many years together, but watching the love of your life slowly physically and mentally deteriorate and suffer tries one's faith.