Does it have anything to do with the fact I was practicing 4-5 hours a day as well? Is it any type of a repetitive stress injury? I know I probably don't have good technique, but I've never injured myself on any other song. Before this etude I also had never practiced for longer than a hour. For the past three days though I spent most of the day repeating the same section over and over again, without much break in between. Could that play a factor as well? I know I have to fix my technique, I was just wondering if that had any effect on my hands. Also should the pain wear off if it give it time to rest from what you've heard? It feels like it may be a nerve problem rather than something with my tendons.
My harsh advice: If you are being serious with this, then you should take a month off from piano playing. I mean it, a month OFF.
This is not what people want to hear, and then we get the usual bunch of "losing too much", "getting out of shape" and "I have to practice" and blablablah. But look, if piano playing is a lifetime commitment for you and not a fad, you have to think in LONG TERMS.
I have been there too. Took up piano playing again and suddenly found it was great fun and so I practiced and practiced ... and then I got physical "sensations" and even trouble. Tried to rest a bit, tried to adjust my technique - also got myself a teacher and so on. It did not help much. What helped me was a long, hot summer when it was virtually impossible to practice for a few weeks because it simply was too hot outside and I was busy with housekeeping and family keeping and other tasks as well.
When I finally sat down at the piano again, the pain was gone! So, recovery time is longer than you think, unfortunately ... longer than you want it to be. But necessary! Yes, you might have to take one or several steps back and start some things over again, but you will regain your former skill faster than you think, and you will be wiser this time.
So be patient here. While you take your piano vacation you can always do other music related activities - learn and memorize music, listen to music, go to concerts, learn more music theory, listen to lectures ... the list is endless. Just don't fool yourself with the popular belief that if you repeat the same three bars 3000 times more, or for yet another 8 hours in a row, you are doing fine. You should NEVER work in that way anyway. Even the best ones avoid that kind of practicing. They may practice for many hours every day - but not all of them do! - but during that time they do a lot of different activities.
Work with one piece for half an hour, the most, then leave it and work with something else. You will learn more efficiently that way! It is not about your fingers, mind you. It is about your brain, and it can just process and digest a certain amount of new knowledge at a time, then it need to take a long break, preferably sleep as well. Don't worry that you are not learning efficiently this way, because you are. The brain keeps on working with post-processing on a subconscious level, and that is just as important as the "actual playing".
A typical sign of mental overload is, if you are lucky, lost of focus and concentration. If you are too engaged, though, you might instead experience that learning gets harder and harder ... and if you try to compensate by working even HARDER, your whole body starts to protest. You feel ache and fatigue and all kinds of nerve reactions. Yes, your brain is directing your body, hopefully ... and these are signs that it is going a bit out of order.
So, await your bench and you teacher, enjoy your summer and be sure that you are doing a wise thing, something that will benefit you the best in long terms.