Hey, so I resolved the problem by just letting the battery die out on its own. Then, I recharged it and turned it on. It only works with the optional cable now. It won't connect using Bluetooth so I'm struggling with that. But at least it works with the cable.
You could try getting the power button fixed because you're gonna eventually have to get it fixed anyways. And sorry if this isn't super helpful, but I don't have that kind of phone so I don't know what else to tell you.