The Infinity Gauntlet is seemingly damaged - we can assume that Thanos probably won't be able to use all the infinity stones together again due to level of damage to the gauntlet - but it is just a container. The most important thing is that Thanos still has all of the Infinity Stones, which essentially makes him the most powerful being of the Marvel Cinematic Universe.
So my question is, now that the gauntlet is destroyed are any or all
of the stones destroyed?
Thanos was able to use the space stone to teleport away after the Gauntlet was fried, which means stones are not destroyed. At least space stone is not destroyed for sure - others seem undamaged as well.
I think this sums it up well enough and explains why the gauntlet might not be useable anymore, but Thanos still has all the stones.
This is actually pretty smart on the part of the writers and
directors. It makes Thanos just powerful enough to be a huge threat
(he was almost untouchable with just four stones), but not powerful
enough that there's absolutely no chance the Avengers can beat him.
It's a clever way of balancing the playfield a bit while still having
the Avengers be the unquestionable underdogs in this scenario. The
heroes need some way to undo all the death caused by the Mad Titan.