I get where you're at, OP. It's a tricky adjustment when you move on from a phase that you've really enjoyed. My kids are a bit younger than yours (oldest on the cusp of 13), and things are shifting; the days out that used to be bankers aren't anymore. So I've been thinking about this a lot and also looking back to when I was a tricky teen.
I haven't read all the posts, but I agree with what others have said about adjusting expectations as to what teens will be up for/potential for silence/sulleness!, but equally not to pander to all demands. For example, I absolutely would not let my children (at the age) dictate that the family holiday would not go ahead. A PP made a good point about framing it well, though; how you express it will matter, I think.
When you are on holiday, I think it's good to give some space. When I was 13, I remember my mum saying I could get up when I wanted and the mornings were my own, but after lunch we would do something as a family, and it worked really well. We usually did caravan holidays, and I'd do stuff on site with my brother in the mornings; we'd all go out locally in the afternoon, and the evenings, we'd also have space, because we'd go to the clubhouse and hang out in the arcade while my parents had a drink.
As for the trips out, when we go away, we all say one thing that we really want to do while we're there, and then we all accept that we're going to do that together. My oldest is all about theme parks or water parks, so we make sure that happens and usually quite early on. On our last holiday, my choice was an hour-long boat trip, nothing my oldest would ever have chosen, but he sat there okay while we went about. I wouldn't say he was loving it, but he wasn't hard work either. Basically, I think you have to introduce the idea of give and take.
Lastly, I would definitely do some more stuff for yourself. I've picked up exercising properly again for the first time in years. I'm really enjoying it, and while I do miss those younger days with the kids and I haven't quite got into this new phase, it is nice to focus on me a bit more and takes the edge off when I do feel a bit sad about time marching on.