Water Damage. What Do I Do?

Hello.

I feel like a total idiot, but yes I dropped my 1.5 month old iPhone 5s in the toilet. Of course I freaked out, grabbed it, dried it off, and turned it on to see if it still worked. It appeared to work fine so I breathed a sigh of relief and didn't even think to turn it off. However, a few minutes later it started acting weird and so I tried to power it off but by then it was too late and it wouldn't allow me to "slide to power off." I was not home at the time so I could not google it to see what to do either. By the time I got home, a few hours later, it was almost dead, so I ran and plugged it in. I know, rookie mistake. It started charging so I took that as a good sign and then went to google it. Of course the first thing it said was to power off and under no circumstances plug it in to charge it. Once again I started freaking out. I immediately unplugged it, removed the SIM card and placed it in rice in a sealed bag. My question is: where do I go from here? How long should I leave it in the rice? Whats my best option? Should I just get a replacement phone from Apple for $300+- even though I don't have money for that? Should I try another way to fix it? Should I bring it to a non-Apple-certified local phone repair place? Is there a way to prevent the insides from corroding? Basically just please tell me what to do!! Any suggestions will be greatly appreciated.

Thanks in advance.