I think that a lot of people think that it is wasted time being depressed but I think it is worthwhile. I feel that contrarily, being mournful can mean being alive because you think of these people that you have lost, and you think of them deeply.
And the day you go too, you will no longer think of them deeply and that is a loss.
So, do not regret this time. It may be the most valuable time of all. How are we to know it is not.