O.k., first thing I always do is read the lyrics, then listen and read along. I have to tell you, I didn't expect the music to be quite so up-beat.
Loss, major loss, unless experienced is all but impossible to understand. Everyone feels loss differently. Some people mourn a divorce (loss of relationship) just as much as someone else may mourn the loss of a person. Or a pet. Or a job.
It does read pretty broad in description. Like, you 'remember the good times' and all that stuff like Mr. Sullivan was saying in his comment. It is kind of generic sounding. Were you married to her when she passed? Did you know her for your lifetime? Children together? Plus I'm left wondering how you feel other than lonely and that you miss her. Which go hand-in-hand anyway.
I think it's def worth working on, and I'm not bashing it in the slightest. And I understand this is a fiction based thing for you personally. I'd ask around to some friends at home that've had a loss and find out how they feel, cause for me I still feel the same years later as I did with the initial impact of the loss.
Rock on, man.

I have music for all of my songs and they vary from rock to country to folk and everywhere in between. (except rap)