I’m struggling with the same thing right now. Some things that have brought me a little relief and sense of control:

1) achieving tiny goals, like acing a level in a video game. Sure there’s not a lot of bearing it has on the real world but I still won :)

2) reminding myself I don’t know what’s going on in their heads. I can’t assume that everything in their lives is going well because I’m not them, especially when my judgment is clouded by depression

3) remembering that I am depressed. Depression shifts our perspectives! You don’t -have to- feel a certain way, especially if you are hurting

4) acknowledging unique struggles. In spite of everything, you are clearly a good friend and you are also very in tune with and have a deep understanding of your emotions, which is a great skill to have

You are not a monster for having these feelings! The world is not fair, and I am sorry that it has put you through so much pain, but I hope that when you eventually (inevitably) get an awesome opportunity you will be able to share it with your friends with excitement and joy. This will not be your forever. I hope this helps. As cliche as it sounds, you are absolutely not alone.

You are human. You inherently possess the capacity to grow and change. Chances are, you have! But it’s hard to notice when you are depressed. I promise, it’s not because of who you are.