Henrix
Explorer
I only came to this forum after I had decided I was probably going to leave the game and yes,
It seems to me that indeed you should leave the campaign and find another that suits your style of play more. For the sake of the whole group, including you.
The campaign he wants to run is obviously one where a character is not just the sum of her powers, and probably has a fairly slow pace. (If something like six encounters spread over the whole day is slow. Sounds too much for me.)
Obvious mismatch between player and DM. And a bit of bad communication, perhaps.
The latter not alleviated by taking it to several forums in anger.
The DM is probably used to players who are fine with small adjustments of the rules to make it fit the narrative better.
I find the rule fine. RAW (sic!) is also clear on that the rules may vary depending on the campaign (and DM). The suggestions for how to deal with that is as yet unknown to us.
Eight hours between short rests is perhaps more than I'd set, but I can easily see why you want a period between rests for them to be meaningful. I'd stick to three hours or so.