Unresolved grief can last a lifetime. The old adage, "Time heals all wounds" is simply false. It is what we do with the time that determines if we are moving toward a healthy recovery from the physical death of a loved one. Unresolved grief stems from unfinished emotional communication ... things we needed to say to, or hear from, our loved one but were unable to do so.
One thing I've learned from communicating with people on the other side is, they can still hear us when we talk to them. This may be hard to believe, but it's true. Messages from those in spirit have shown this time and again.