@trying2learn,
I'm sorry TTL, you're wallowing in self pity. It's narcissistic. My wife died just over nine years ago leaving me with two children, I didn't really have time to stay devastated, my kids needed someone who could move on and think positively.
You need to move on now, this behaviour is self destructive and extremely narcissistic. Everybody suffers, your suffering isn't anymore important than others. You need to suck it up and move on. It's not easy, but it needs to be done, not only for your sake, but the sake of others, particularly your niece.
Lot's of things are out of your control, but staying miserable isn't. Misery is a state of mind, you can choose to be cheerful if you want to. It really is that simple.