How to leave a widower who doesnt want anyone but his wife?

im 39 my bf is 46, his wife passed almost 4 years ago. We had a child who is 17months old. Our relationship has been healthy so far. We talk about his wife when he needs to. He suddenly feels guilty and overwhelmed with the life he has. I know he needs to grieve but im worried about how it will affect his only child. I know he needs help. I know I am in his life for a reason. is it a coincidence that his wifes name and my nick name are the same? I found this out after we started dating