I understand how you feel. I often have often felt that I am living beyond my conscious will. That my inherent survival instinct is all that was driving me to continue. I think most people with cancer struggle with having feelings that do not match the way they think they should feel, but you can feel anyway you want about your situation. Often it takes a long time to digest the insane and impossible situation into which we have been thrust. I have had days when I get bad news and my reaction is to just keep going. Work can provide a meaningful distraction from all the bad news. I am sorry to hear that you do not have family close to help support you. I do not know if this is helpful but there are organizations like Imerman Angles or things like the Stupidcancer app that can provide you with one on one peer support, these helped me when I was diagnosed. If you want someone to talk to you are welcome to message me.
It's funny I was just about to write a post exactly like this. It's really weird that cancer can become normalized. I think most people just expect you to be nothing but exhilarated that you've beat cancer, but there's more to it. You've been through this major event and just because treatment is over doesn't mean that all the feelings that have been brought up are just going to disappear. If someone survives a car wreck they're going to be happy to be alive, but that doesn't mean that there aren't going to deal with the lasting effects of almost dying. You have to give yourself a break. It can be hard when you read all this stuff about people beating cancer and then climbing a mountain. Everyone deals with things in a different way. I'm sorry if I sound cliche, but allow yourself some time to take stock. Think about what makes you happy and take small steps toward that. I often put a lot of pressure on myself about making everything count, but it's unhelpful. Find strength in the fact the you survived one of the worst things that can happen to anyone. You should be proud of yourself for continuing to work, for getting out there and being a part of those weddings. Just taking part in day to day life after such a life altering event is heroic in my book.