While I think doing things to help our sense of well-being is a very good thing, I’m not sure if it should come at the expense of being honest with ourselves about how we feel. It’s OK to feel sad or angry or hopeless - there’s nothing wrong with these emotions themselves, and they’re perfectly normal things to expect given what’s happened. Allowing space to grieve the change in our health is very important. I know I want to try & bottle my emotions up a lot of the time, but sometimes it’s good to just have a good cry or rant, and I always feel better for it afterwards.
That said, there are things we can do to help lift our mood. Listing things to be thankful for is well known to help people’s levels of happiness. Another surprising thing is to fake smile - when we smile, our brains release so-called happy chemicals that lift our mood. The interesting thing is that our brain can’t tell the difference between a genuine smile and a fake one, and will still release the happy chemicals. So throughout the day, just lift your brow so you’re not frowning and do a smile for a minute.
Another thing that might help is to do a regular review at the end of the day or the week, where you look back and find those things that energised you, where you felt alive somehow, or that felt wholesome or nurturing, or gave you a sense of satisfaction, even if only a little bit. Then look for those things that had the opposite effect - that drained you, that left you feeling empty etc.
As I’ve done that over time I’ve found similar things come up. So I know now that just watching telly all night leaves me feeling empty & frustrated. And I know that engaging with nature is very good for me, even if it’s just looking at the sky and clouds for 15 minutes. Doing something expressive is very good for me too, like doing somewriting of some sort, either about how I’m feeling or something more creative.
I hope that makes sense, and I hope you start to find yourself again.