My iPhone Pushes All The Wrong Buttons?

I have an iphone 3GS and it was working great then all of a sudden I noticed it would be hard to slide the unlock button. I'd have to try multiple times to unlock my phone. It was like my finger was slipping, but it wasn't my finger. Then it would start pushing buttons I didn't want when I text. It's extremely hard for my to text now because my phone will press the space bar or it won't press 'n' or 'u' and so on. Now it opens apps without me touching anything. I've reset the phone, I just tried recalibrating the home button. What do I do because nothing I have tried works. It's extremely frustrating. If you can help please let me know. I'd rather not have to pay out my *** if I can just attempt to press a few buttons to get it fixed. Thanks.

Added (1). I'm not looking for you to tell me to take it to the store or anything of that sort. I'm not ignorant. I know I can just take it to the store and they can tell me the problem. I go back to my previous statement of not wanting to pay out of my *** if I can just do something here at home.

I've had a 3GS a long time and never had an issue, but I know someone that had a 3G and the screen wore so some areas didn't work well, but that was old technology then compared to today and after alot of use… So I doubt if thats the same issue you had. 3GS is now free with a 2 year plan, if you have a phone issue and your contract is up then you can probably just get a new 3GS phone with a 2 year extension.

Bring it to the apple store so they can tell you what's wrong with it. Maybe the screen is shifted or moved a little so its harder to know where to push or slide the buttons.