Anyhow the best piano tips I can give you is to study something more difficult. Like, when you're at that point where things are impossible no matter how much you try and you're considering taking up fishing instead, start on something even more impossible.
From my experience, it's hard to stay equally desperate and equally stuck on two things at the same time, so the more impossible thing will suck up the despair, and then when ten or twenty minutes later you go back to the less impossible thing, you'll not only find it much easier (because you've been practicing something much more unreasonable) but also your mind will start thinking "well at least it's not like that other demonic thing from hell" and you'll be more relaxed and lo and behold you'll manage to play it. Works every time.
(I'm kidding of course but also not so much)