That's just how shit goes. You can fight it, you can cry about it, you can hate it all you want. Things change. There is no trick to accepting or dealing with this. You just have to, or you live the rest of your life being miserable about how different things are. It's hard and it hurts and it takes effort to handle it.
Now, if it's not hard, or if it doesn't hurt, things didn't really change - they just look different. They're still the same, you just don't realize it. When things DO change, for real, it hurts, if for no other reason than you realize that everything you know (or thought you knew) about a situation is wrong, and there's no easy way to handle that. If you don't believe me, ask anyone who has lost their religion.
When you realize that things have changed - not while you're suffering through it, but after all that pain and anguish... The moment of clarity you experience when you see the world for what it is through the fog of what you thought it was - that's when you have your choice. That's when you can either rebel, and attempt to push everything around on the board back where it was so that the playing field looks more familiar, or you can learn the new rules and work your ass off to get good at the new game.
As for me, I'm not one to ever give up. I never have. I have quit things before, because there's no shame in realizing you're not made for a thing or a place and leaving it. But I've never surrendered, and I've never given up. Quitting is a decision, surrender is the abandonment of spirit. And I've been through an insane amount of change the past, oh, three months or so. The world is different now.
It's a short, small statement, but it means everything to me at this point in time. The world is different now. And I'm learning how to live in it. And it's taken everything I have, and it's asking for more. But I can make more.