My iphone 4s only works when plugged in, experiences random crashes, and the wifi is grayed out?

Question

First post here. I'm experiencing some pretty complicated issues with my iphone 4s of several years, which began yesterday at random. I'm sorry for the length, but if someone could read through all of this and help me out, I would be so grateful.
I started experiencing some complex issues with my iphone yesterday, seemingly at random. I was taking a phone call, and all of a sudden, my phone goes dark. The battery was between 50%-80% at the time. I immediately plugged it in, and the apple logo appeared and began to power on. When it came back on however, I immediately noticed some changes. For starters, the battery leapt to 100%. The top corner of my phone where the carrier and bars should be says "searching..." (this never goes away). When I go into settings, the wifi is grayed out and says "no wifi."
That's not the worst of it though. As of last night, the number of times my phone crashes has gotten progressively worse. Now, even when I plug my iphone in to a wall charger, it stays on for maybe 1-4 minutes before it crashes completely. After this, it sometimes restarts itself. Before the shut-down, there are usually some weird bars or colors that flash across the screen (it's always different). I'm running on ios5 (I just really like the layout so much more, so I never bothered updating).
I don't think I did anything out of the ordinary to my phone. I walked in the rain for a short while when it was in my back pocket, but I've done this many times before and I don't see how that could create massive water damage. Also, it worked perfectly fine for a few hours after I got home. Quite literally, this just happened out of the blue. No warning, no signals, nothing. So far, I've tried...
- turning it on and off (duh)
- doing a hard reboot by holding down the middle and top buttons, several times
- resetting the network settings
- turning off data roaming and toggling airplane mode on and off
I even attempted the freezer trick. I didn't put the phone in the actual freezer because I was worried about condensation, but I did set it down on an icepack. This seemed to keep it alive a little bit longer before crashing, but only marginally so. My original plan was to plug my phone into my computer and download all my pictures and whatnot before attempting a complete data wipe and factory reset, but this also seems impossible. When I plug the phone into my laptop, the little apple logo comes and goes, but it simply never powers on fully. And even if it did, I doubt it would stay on long enough for me to complete a download without things crashing.
I'm totally lost here. Is my phone wrecked? I'm sensitive about my privacy, so I'm not crazy about the idea of taking my phone to the apple store and having them make some sort of copy of my data. I'm also not crazy about uploading all of my phones data to iTunes or the cloud or something like that. In addition to this, I don't know how I would salvage my in-app data. That's also something I'm worried about. I can't attempt to update my ios without wifi or the ability to plug my phone into a computer. All of this would be a lot easier if I could keep my iphone on longer than 2 minutes.
I've had this phone for years. I really don't want to just let it die at random and never even know why. I just feel like this hit me out of nowhere. Any suggestions about what I could do? I'm willing to try everything. I'm planning on calling apple, but I was thinking of asking online first.
BONUS: if anyone could answer these extra questions (you don't have to), that would be awesome! When you do a complete data wipe and restore your iphone to factory settings, where does all of your data go? Is it actually *gone* for good? I'm not just talking about photos, but also internet history, in-app data, and youtube history from the youtube app. Does it disappear completely? Or does it get stored somewhere. Also, is there anyway to downgrade a new iphone to an earlier ios without jail breaking it? I've pretty much lost hope with this phone, but if I get a new one, I just wish there was some way to keep using the old ios I'm used to.
Thanks so much to anyone who can answer these questions.

Answer 1

I have tried everything
If that is the case, by definition there is nothing left you can do...
Did you try connecting to another computer?  Did this computer ever detect the phone?  Does the USB system on your computer work normally with other devices?  What is your computer OS version?  iTunes version??