I wouldn't give up the piano - you passed grade 1 so you evidently are learning to play.
OTOH, there might be something to give up, or at least change, that's causing your lack of progress.
That could be the teacher, as some have said, it could be the way you're practising or it could be your goal between lessons is too high - not for your ability, for your available time.
e.g If you didn't complete a simple piece you were given, could you have done 1/2 the piece, a 1/4 or even less, just a few bars?
If so, then a grade 2 piece, typically around 24 bars, might take several lessons, but you'd be making noticable progress on the parts of the piece you could play. I get the impression that you're practising a whole "simple" piece in one go and then, if you haven't learnt it, thinking you've made no progress?
If you have another spare 30 minutes with the teacher not knowing what to do, ask them to watch you practise the piece, and see whether they think your practise is effective - if they think it is then say "It must be the teaching then"

Nah, don't say that

Hopefully they will give some pointers.
There's a heap of posts about practising methods in the forum where some of what I've said above [and lots more] is discussed in greater detail, read through some of those and try them.
As for the current situation - try and forget what the teacher said - practise a few bars or even one bar that you can't play - the hardest one in the piece, until you can play it [using the advice in the posts on the forum] - when you learn to play that, then you'll know that you can learn to play something you couldn't before and that it was the hardest bit - the rest of that piece is going to be easier - except for one thing - the temptation to not practise the rest in the same methodical way because you can play part of it.
If that makes you start to enjoy it again, then relate the enjoyment to the successful results of practise, even if the practise itself isn't always fun per se.