Thanks for your help, but this question was hiding a bigger one.
So until today, my phone has been working just fine. I'm still running an old, now outdated and unsupported ROM: ShirshirROM pre-alpha ICS. It's been my daily driver for almost a whole year now, works perfectly with Entropy's old ICS kernel.
Yesterday, I got tired of shell errors with Superuser (which I had been dealing with since the latest binary update), so I finally switched to SuperSU. Everything seemed to work fine afterwards, though I noticed some trouble with the power button being a little wonky, i.e. showing up the power menu when I hadn't pressed it or not immediately responding.
Today, my power button doesn't work correctly at all. I tried wiping cache, dalvik, then restoring a Nandroid of the same ROM/Kernel combo from way earlier this year. Key test in CWM also shows that all buttons register when pressed, EXCEPT the power one. Otherwise phone functions are perfect; I can make calls, send/receive texts, etc, I just have to plug in my phone or have something happen for the screen to turn on, and then I have access to everything. My question is, is this (God forbid) a hardware failure? That would be my worst nightmare, seeing as I'm almost exactly one full year out from contract renewal, and I don't have a lot of money to spend on a new one, nor do I have nowhere near enough expertise to try to fix it myself. What can I do?
P.S. The TiBu question was because in case the Nandroid fixed the problem, I could just restore contacts and SMS from TiBu since it is the same ROM, and be back up and running immediately.
P.P.S. As mentioned, I can get into CWM. This is done by pulling battery, sticking it in, and holding all physical keys until boot screen shows twice. But I can't use the power key to select any options, I have to use home. And key test shows the power button not registering. I'm hoping that that means power key may still work, but that's just me praying this is fixable.