I am sorry that you are depressed. I know how you feel, and the upcoming wedding will not help either.
You are still "fairly early" at this. Look at me, it has almost been four years and only now I start detaching more and more and I don't wake up anymore with my first thought being XH. But he is STILL very often on my mind and I get sad on some days.
I have the feeling that time does not completely heal the wounds but it surely helps. And GAL and a job also help. One day you will also get there.
I wish you strength for the upcoming wedding. (((HUGs)))