First, it is helpful to understand your sorrow—the parts that comprise your sorrow. You are sorrowing because you are in the process of losing something. Grief is all about loss. You are not only losing your loved one, but the office that individual has filled in your life. You are losing the role of a companion. And you are losing the lifestyle that you have had, and you are aware that sometime soon you will be creating/morphing into a new lifestyle. All change is difficult, even changes that involve improvements. So, it is natural that your emotions are responding to what your intellect calculates is happening, to your "knowing" that something different is going on.
You can also be helped by thinking about getting on with some good healthy strength in involvement in your own life/future and independence. It is appropriate to grieve but not to be slayed by your grieving—not to become non-functioning. Because we can cast these big events upon God's sovereignty, we can ride them with confidence and a sense of well-being. He is in control of everything—and sometimes we just hang on for the ride through life's passages—all of which we've never been through before. Loss of control, of total ability to manage all the variables in our life, is actually the beginning of trust. God has BIG SHOULDERS.