Perform a backup of your iOS in itunes, if you relay on unlock then save shsh of yout device with tinyU, restore to the same iOS you are having at the moment. After that, restore your backup and see if the issue is solve, but if it's a corrupted file inside the files you've backuped causing that issue, you will have the same issue after restoring your backup. So you can find it out by playing with the device a while after a fresh restore to make sure that your home button is ok. Then restore your backup and see how it goes with your home button.